A normal link would be like this:
HTML Code:
[URL]http://www.bimmerpost.com[/URL]
What you want looks like this:
HTML Code:
[URL=http://www.bimmerpost.com]Click here[/URL]
See the difference? You can also use the link button of the editor (a world symbol with a 'link'), it asks for the link first and when you see the marked text in the editor next just type in your 'Click here' or whatever you want.
Best regards,
south