#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?u)<secondary_references>(\[id=(\d+)\]([-, ]{0,2}))*</secondary_references>"
Local $sString = "<secondary_references>[id=1],[id=2]</secondary_references>" & @CRLF & _
"<secondary_references>[id=1]</secondary_references>" & @CRLF & _
"<secondary_references>[id=1]-[id=2]</secondary_references>" & @CRLF & _
"<secondary_references>[id=1][id=2]</secondary_references>"
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