Well, for static IP you should ask your service provider, they'll cost you a couple hundreds more. As for your friend's IP that's a dynamic address (DNS) that's what I was talking about.
Go there:
http://www.no-ip.com/ Download and install thier client for Windows run, create an account and you're done. You need to register your DNS name like SaadGenius.no-ip.org or et cetera. For further RTFM!