#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)(\b(DIN)|(DIN EN)|(DIN EN ISO)|(DIN ISO)|(DIN-EN)|(DIN-EN-ISO)|(DIN-ISO)|(EN)|(IEC)|(ISO)|(NEN)|(NEN‑EN)|(NEN‑EN‑IEC)\b)(\s)(\d)"
Local $sString = "You can find the specifications in DIN 12345, DIN EN 12345, DIN EN ISO 12345, DIN ISO 12345, DIN-EN 12345, DIN-EN-ISO 12345, DIN-ISO 12345, EN 12345, IEC 12345, ISO 12345, NEN 12345, NEN‑EN 12345, NEN‑EN‑IEC 12345."
Local $sSubst = "$1‡$3"
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