#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "\\u(\w{4})"
Local $sString = "^(?:[A-Za-z0-9\u00C0-\u017F\u20AC\u2122\u2150\u00A9 \/.,\-_$!\'&*()="?#+%:;\<\[\]\r\r\n]|(?:\ud83c[\udf00-\udfff])|(?:\ud83d[\udc00-\ude4f\ude80-\udeff]))*$"
Local $sSubst = "\\x{$1}"
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