Is there a way to do this?

[ozsd]

Ok I'm working on a site and I've been trying to figure this out for sometime now. I know I've seen it on several sites but I dont know if its done with mod_rewrite as I'm new to this sort of thing.

Ok I would like something like this

http://username.mysite.com/page/data/ect/

with the subdomain as a variable not actually pointing to a folder