#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)^(.|\n){240,}$()"
Local $sString = "12345678901234567890123456789012345678901234567890" & @CRLF & _
"12345678901234567890123456789012345678901234567890" & @CRLF & _
"12345678901234567890123456789012345678901234567890" & @CRLF & _
"12345678901234567890123456789012345678901234567890" & @CRLF & _
"123456789012345678901234567890123456"
Local $sSubst = "$2(\$2)is for replace all text with nothing (remoove all text)"
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