Hm okayy... i just read in google that its possible and eazy to activate that in a forum if you have the rights. Is there any way to add that BBcode into forum?

I thought this BBcode would work
Link opening on same page: [surl]URL[/surl] or [surl=URL]Display text[/surl]

Also exists:
URL = <a href="URL" target="_blank"></a>
URL = <a href="URL" target="_self"></a>