#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?i)(\[bold\]?)(.*?)(\[\/bold\]?)"
Local $sString = "Hallo [bold]ik[/bold] ben een zin [bold]met bold[/bold]"
Local $sSubst = "<CharacterStyleRange FillColor=""> <Properties> <AppliedFont type="string">$2</AppliedFont> </Properties> <Content>Hallo</Content> </CharacterStyleRange>"
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