Oder so:
[autoit]#include <Timers.au3>
Local $hTimer, $hGUI
$hGUI = GUICreate("")
$hTimer = _Timer_SetTimer($hGUI,10,"_NoMouseMove")
Do
Until InputBox("","Passwort eingeben") = "geheim"
_Timer_KillTimer($hGUI,$hTimer)
Func _NoMouseMove($hWnd, $iMsg, $wParam, $lParam)
MouseMove(0,0,0)
EndFunc