#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(<title>((?:(?!<\/title>).)*)<\/title>\s*<content>)((?:(?!<\/content>).)*)"
Local $sString = "<xml>" & @CRLF & _
" <item>" & @CRLF & _
" <title>Title 1</title>" & @CRLF & _
" <content>Text 1</content>" & @CRLF & _
" </item>" & @CRLF & _
" <item>" & @CRLF & _
" <title>Title 2</title>" & @CRLF & _
" <content>Text 2</content>" & @CRLF & _
" </item>" & @CRLF & _
"</xml>"
Local $sSubst = "$1$2 $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