routing subdomain request

[FunFun]

Give how to do this trick:
1. Users were tables with one of the fields and table subdomain
Blogs class Blog <ActiveRecord:: Base
has_many: comments
belongs_to: user
class User <ActiveRecord:: Base
has_many: blogs
2. There is a module which writes in account_subdomain subdomain
address from the browser
3. The objective to have at domain.com / blogs drawing record all
users, and sub.domain.com/blogs write only user's subdomain which
"sub" How? Thanks!