#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)(?P<set>(?=^\d+(?:\(|$))(?:\d+)|(?=\d+\)$)(?:\d+))(?:\((?P>set))?"
Local $sString = "123(456)" & @CRLF & _
"123" & @CRLF & _
"abc(123)" & @CRLF & _
"123(abc)" & @CRLF & _
"abc(def)" & @CRLF & _
"1()" & @CRLF & _
"00000(00000)"
Local $sSubst = ""
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
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