How do I create member subdomains without wildcards?

Is there a way to automatically point a directory (domain.com/user/myname) to a subdomain (myname.domain.com) without using DNS wildcards? If so, how?

PS: I do have mod_rewrite

 

Bump. Still need help, please!

 

Is really easy just create a php redirect, check this: http://es.php.net/header

 

Simply not possible.

If you type in sub-domain-that-does-not-exist.domain.com and you do not have a wild-card record setup the request will never even hit your server.

You could do this doing it like domain.com/users/anything-your-user-wants