Ahhhh. Well. If what you want is for your code to be able to identify URLs and wrap them in links, then using regular expressions is the way to go.
Another path is to have the user add the link element themself, just as they now add the BR tags.
There are other ways to deal with this as well, and it depends on how much of the process you are in control of. If you are providing the editor, then you can add features to your editior that allows the user to mark text just like they do here on this forum. for example.
Woody Z
http://www.learntoprogramnow.com