#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?m)\[(url=https://www\.translatum\.gr.*?)\[/url]"
Local $sString = "Test aetejklkj fa jklkj dsdfs [url=https://www.translatum.gr/forum/index.php?topic=989146.0]telerobotically -> τηλερομποτικά, τηλερομποτικώς[/url] fskjlkj " & @CRLF & _
"Gfdsklkj fjgkjkl klkjdass" & @CRLF & _
"" & @CRLF & _
"[url=https://www.in.gr/]in.gr | Όλες οι ειδήσεις - Ολοκληρωμένη κάλυψη ειδήσεων[/url] Gfdsklkj fjgkjkl klkjdass Gfdsklkj fjgkjkl klkjdass Gfdsklkj fjgkjkl klkjdass Gfdsklkj fjgkjkl klkjdass Gfdsklkj fjgkjkl klkjdass" & @CRLF & _
"" & @CRLF & _
"Gfdsklkj fjgkjkl klkjdassGfdsklkj fjgkjkl klkjdassGfdsklkj fjgkjkl klkjdass Gfdsklkj fjgkjkl klkjdassGfdsklkj fjgkjkl klkjdassGfdsklkj fjgkjkl klkjdass "
Local $sSubst = "[i\1[/iurl]"
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