#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?s)\[(.*?)\]\((\S*?) ?('(.*?)')?\)"
Local $sString = "[Descriptive text](https://example.com/ 'Title text')" & @CRLF & _
"" & @CRLF & _
"[Descriptive text" & @CRLF & _
"Accepts linkebreak](https://example.com/ 'Title text" & @CRLF & _
"Accepts linkebreaks')"
Local $sSubst = "<a href="$2" title="$4">$1</a>"
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