Rewriting subdomain

[madmax728]

Is it possible to rewrite a subdomain like
http://hello.abc.com
Into
http://www.abc.com?u=hello

I have seen people doing this using .htaccess file.

[alexjdb]

Why would you need to do that ?

I don't see where they would use htaccess, however you can do this with php.

[madmax728]

No, it can be done using .htaccess It's just like rewriting
http://www.abc.com/text/hello into http://www.abc.com?u=hello

I want the same effect with sub domain