rewrite with subdomains

[macdar]

Hi,
I'm trying to rewrite my dynamic php code into html.

RewriteRule ^index-(.*).html$ /index.php?pg=1
it works but only in the main directory.
But the problem is that the php script is not in the main dir but in subdomain.

so, I would like to have:

[sudomain.domain.com...]

instead of

[sudomain.domain.com...]

[WhosAWhata]

put the .htaccess file in the subdomain