Hi Janine,
A redirect can be done in a number of ways on your domain. I usually use PHP coding as I find it responds the fastest. Here is a post with a few ways of doing a redirect:
http://www.webconfs.com/how-to-redirect-a-webpage.php Let me know if you need help with how to set this up.
When you say "shortened" do you mean the custom URL? I think I am understanding correctly. To get the custom URL when you hit 25 fans go to:
http://facebook.com/username and click on the link that says "Set a username for your pages"