htaccess subdomain id category

htaccess subdomain id category

plz i want change categories to subdomains with htaccess: Example this is
my url
http://my-url.com/index.php?id_cat=29&l=category-name-here
and i want to rewrite it to :
http://category-name-here.my-url.com
and this is what i try but i cant find what i want
Options +FollowSymLinks
RewriteBase /
RewriteCond %{HTTP_HOST} !^www.your-domain-name.com [NC]
RewriteCond %{HTTP_HOST} ^(www.)?([^.]+).your-domain-name.com$ [NC]
RewriteRule ^([^.]+)$ /some_file.php/$1?subdomain=%2 [L,QSA]
thank you