#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "("[^"\\]*(?:\\.[^"\\]*)*"|'[^'\\]*(?:\\.[^'\\]*)*'|`[^`\\]*(?:\\.[^`\\]*)*`)|\\n"
Local $sString = "\nnew"test\naaaa\\\n"\nta\n`this is a \nnewline that should be kept`\n'this is a \nnew test'\n" & @CRLF & _
"" & @CRLF & _
"Have a look at "\\\n""
Local $sSubst = "$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