Subdomain to load controller

[eluser]devastator[/eluser]
Hello and Merry Christmans to all.

I want to make this url subdomain.mysite.com to opens mysite.com/controller/
How to make it? I try this but i have 500 error ...

RewriteCond %{HTTP_HOST} subdomain.mysite.com
RewriteCond %{REQUEST_URI} subdomain.mysite.com
RewriteRule ^(.*)$ index.php/controller/$1 [L]

and this

RewriteCond %{HTTP_HOST} ^subdomain.mysite.com
RewriteRule ^(.*)$ index.php?/controller/$1 [L]