$hGUI = GUICreate("_StringReplaceEx",400,475)
$edit = GUICtrlCreateEdit("I am a text, containing the world Hello."&@CRLF& _
	"Hello used to be a very important word in the english language."&@CRLF& _
	"Without 'Hello', nobody could greet another person."&@CRLF&@CRLF& _
	"I am a text, containing the world Hello."&@CRLF& _
	"Hello used to be a very important word in the english language."&@CRLF& _
	"Without 'Hello', nobody could greet another person.",20,20,360,300)

$Search = GUICtrlCreateInput("Hello",150,330,200,25)
GUICtrlSetTip(-1,"The substring to search.")
GUICtrlCreateLabel("Search:",70,335,-1,25)
GUICtrlSetTip(-1,"The substring to search.")

$Replace = GUICtrlCreateInput("Good morning",150,360,200,25)
GUICtrlSetTip(-1,"The replacement string.")
GUICtrlCreateLabel("Replace:",70,365,-1,25)
GUICtrlSetTip(-1,"The replacement string.")


GUICtrlCreateLabel("How Many Times:",20, 400)
GUICtrlSetTip(-1,"The number of times to replace the searchstring."&@CRLF&"Set this to '0', if you want the function to replace all occurences of the searchstring,"&@CRLF&"starting with the determined occurence in $iOccurence"&@CRLF&"Use a negative value, to search from the right to left.")
$HowManyTimes = GUICtrlCreateInput("2",125,395,50,25)
GUICtrlSetTip(-1,"The number of times to replace the searchstring."&@CRLF&"Set this to '0', if you want the function to replace all occurences of the searchstring,"&@CRLF&"starting with the determined occurence in $iOccurence"&@CRLF&"Use a negative value, to search from the right to left.")
GUICtrlCreateUpdown(-1)


GUICtrlCreateLabel("First Occurence:",200, 400)
GUICtrlSetTip(-1,"The substrings occurence to start with.")
$FirstOccurence = GUICtrlCreateInput("3",300,395,50,25)
GUICtrlSetTip(-1,"The substrings occurence to start with.")
GUICtrlCreateUpdown(-1)


$button = GUICtrlCreateButton(" _StringReplaceEx ",250,430)
GUISetState()
While True
    Switch GUIGetMsg()
        Case -3
            Exit
        Case $button
			$newString = _StringReplaceEx(GUICtrlRead($edit),GUICtrlRead($Search),GUICtrlRead($Replace),GUICtrlRead($FirstOccurence),GUICtrlRead($HowManyTimes))
			If Not @error Then
				GUICtrlSetData($edit,$newString)
			Else
				MsgBox(16,"Error!","_StringReplaceEx returned @error."&@CRLF&"Error Code: "&@error)
			EndIf
    EndSwitch
WEnd



;=================================================================================================
; Function:         _StringReplaceEx($sString,$sSearchString,$sReplaceString[,$iOccurence[,$iHowOften[,$iCaseSense]]])
; Description:      Extends StringReplace(). Giving you the ability to choose the first occurence to start with,
;					and how many times the Searchstring should be replaced.
;
; Parameter(s):     $sString			- 	The string to evaluate.
;                   $sSearchString		- 	The substring to search.
;                   $sReplaceString		- 	The replacement string.
;					$iOccurence			-	(optional) The substrings occurence to start with. (1) by default.
;					$iHowOften			-	(optional) The number of times to replace the searchstring.
;											(1) by default. Set this parameter to (0) if you want the
;											function to replace all occurences of the Searchstring, starting with the one
;											in $iOccurence. Use a negative value, to search from the right to left.
;					$iCaseSense			-	(optional) Flag to indicate if the operations should be case sensitive.
;											0 = not case sensitive, using the user's locale (default)
;											1 = case sensitive
;											2 = not case sensitive, using a basic/faster comparison
;
; Requirement(s):   Valid parameters :P
;
; Return Value(s):  On Success - Returns the new string
;                   On Failure - Returns 0
;                   @Error - 0 = No error.
;                            1 = Function called with invalid parameters
;                            2 = Searchstring was not found at the given occurence
;
; Author(s):        SEuBo (www.autoit.de)
; Note(s):
;=================================================================================================
Func _StringReplaceEx($sString,$sSearchString,$sReplaceString,$iOccurence=1,$iHowOften=1,$iCaseSense=0)
If $sSearchString = "" Or $sString = "" Or $iOccurence < 1 OR $iCaseSense < 0 Or $iCaseSense > 2 Then Return SetError(1,0,0)
Local $i = 1
If $iHowOften = 0 Then $i = -1
If $iHowOften >= 0 Then
	If Not StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence) Then Return SetError(2,0,0)
	Do
		$sString = StringLeft($sString,StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-1)&StringReplace(StringTrimLeft(StringTrimRight($sString,StringLen($sString)-StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-StringLen($sSearchString)),StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-1),$sSearchString,$sReplaceString)&StringRight($sString,StringLen($sString)-StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-StringLen($sSearchString))
		If $iHowOften <> 0 Then $i += 1
	Until $i > $iHowOften OR Not StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)

Else
	Local $i = -1
	$sString = _StringReplaceEx_Reverse($sString)
	$sSearchString = _StringReplaceEx_Reverse($sSearchString)
	$sReplaceString = _StringReplaceEx_Reverse($sReplaceString)
	If Not StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence) Then Return SetError(2,0,0)
	Do
		$sString = StringLeft($sString,StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-1)&StringReplace(StringTrimLeft(StringTrimRight($sString,StringLen($sString)-StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-StringLen($sSearchString)),StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-1),$sSearchString,$sReplaceString)&StringRight($sString,StringLen($sString)-StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)-StringLen($sSearchString))
		$i -= 1
	Until $i < $iHowOften OR Not StringInStr($sString,$sSearchString,$iCaseSense,$iOccurence)
	$sString = _StringReplaceEx_Reverse($sString)
EndIf
	Return SetError(0,$i,$sString)
EndFunc

;=================================================================================================
;#####INTERNAL USE#####
;_StringReplaceEx_Reverse : Reverses the contents of the specified string. (without a dll-call)
;SEuBo (www.autoit.de)
;=================================================================================================
Func _StringReplaceEx_Reverse($sString)
	Local $sReverse = ""
	For $x = 1 to StringLen($sString)
		$sReverse &= StringRight($sString,1)
		$sString = StringTrimRight($sString,1)
	Next
	Return $sReverse
EndFunc
;=================================================================================================