Wieso StringSplit?
[autoit]$text = '\\server\share\order1\dummy.txt'
MsgBox(0, "", StringLeft($text, StringInStr($text, '\', 0, -1)))
Oder mit RegExp:
[autoit]
$text = '\\server\share\order1\dummy.txt'
MsgBox(0, "", StringRegExpReplace($text, '(.+\\).*', '$1'))
Und so "kööööönnnnnnte" man es auch machen: 
$fFile = "\\server\share\order1\dummy.txt"
$array = StringSplit($fFile, '\', 1)
MsgBox(0,"",$array[0])
MsgBox(0,"",$array[1])
MsgBox(0,"",$array[2])
MsgBox(0,"",$array[3])
MsgBox(0,"",$array[4])
MsgBox(0,"",$array[5])
MsgBox(0,"","Dieses String wird gleich nochmals geteilt : " & $array[6])
$2_array = StringSplit($array[6], '.', 1)
MsgBox(0,"",$2_array[0])
MsgBox(0,"",$2_array[1])
MsgBox(0,"",$2_array[2])
;MsgBox(0,"",$2_array[3])
$3_array = StringSplit($array[3], '', 1)
MsgBox(0,"",$3_array[0])
MsgBox(0,"",$3_array[1]) ; = s
MsgBox(0,"",$3_array[2]) ; = e
MsgBox(0,"",$3_array[3]) ; = r
MsgBox(0,"",$3_array[4]) ; = v
MsgBox(0,"",$3_array[5]) ; = e
MsgBox(0,"",$3_array[6]) ; = r
$4_array = StringSplit($fFile, '', 1)
MsgBox(0,"",$4_array[0])
MsgBox(0,"",$4_array[1]) ; = \
MsgBox(0,"",$4_array[2]) ; = \
MsgBox(0,"",$4_array[3]) ; = s
MsgBox(0,"",$4_array[4]) ; = e
MsgBox(0,"",$4_array[5]) ; = r
MsgBox(0,"",$4_array[6]) ; = v
MsgBox(0,"",$4_array[7]) ; = e
MsgBox(0,"",$4_array[8]) ; = r
MsgBox(0,"",$4_array[9]) ; = \
MsgBox(0,"",$4_array[10]) ; = s
MsgBox(0,"",$4_array[11]) ; = h
MsgBox(0,"",$4_array[12]) ; = a
MsgBox(0,"",$4_array[13]) ; = r
MsgBox(0,"",$4_array[14]) ; = e
MsgBox(0,"",$4_array[15]) ; = \
MsgBox(0,"",$4_array[16]) ; = o
MsgBox(0,"",$4_array[17]) ; = r
MsgBox(0,"",$4_array[18]) ; = d
MsgBox(0,"",$4_array[19]) ; = n
MsgBox(0,"",$4_array[20]) ; = e
MsgBox(0,"",$4_array[21]) ; = r
MsgBox(0,"",$4_array[22]) ; = 1
MsgBox(0,"",$4_array[23]) ; = \
MsgBox(0,"",$4_array[24]) ; = d
MsgBox(0,"",$4_array[25]) ; = u
MsgBox(0,"",$4_array[26]) ; = m
MsgBox(0,"",$4_array[27]) ; = m
MsgBox(0,"",$4_array[28]) ; = y
MsgBox(0,"",$4_array[29]) ; = .
MsgBox(0,"",$4_array[30]) ; = t
MsgBox(0,"",$4_array[31]) ; = e
; Und was mag uns diese MsgBox wohl anzeigen ?????????
MsgBox(0, "Test", MsgBox(0, "Test", $4_array[1]&$4_array[2]&$4_array[3]&$4_array[4]&$4_array[5]&$4_array[6]&$4_array[7]&$4_array[8]&$4_array[9]&$4_array[10]&$4_array[11]&$4_array[12]&$4_array[13]&$4_array[14]&$4_array[15]&$4_array[16]&$4_array[17]&$4_array[18]&$4_array[19]&$4_array[20]&$4_array[21]&$4_array[22])
