#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "(?m)^=\?(?<ifNull>(?:\\(\\\\)*:|[^:])*)(?<!\\):(?<ifNotNull>(?:\\(\\\\)*:|[^:])*)$"
Local $sString = "=?This value would be returned if null or empty.:This would be returned if not." & @CRLF & _
"=?This\:is\:a\:demo of what \:happens\:with:an escaped \: separator." & @CRLF & _
"=?This is what happens with an invalid value." & @CRLF & _
"and don't forget the =? on the front of the string:or you won't get any results."
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH)
Local $aFullArray[0]
For $i = 0 To UBound($aArray) -1
_ArrayConcatenate($aFullArray, $aArray[$i])
Next
$aArray = $aFullArray
; Present the entire match result
_ArrayDisplay($aArray, "Result")
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm