strict domain rewrite conditions

[taith]

hello, i have the following rewrite rules, which work wonderfully, however it is overpowering any subdomains i create... does anyone know the rewritecond so that it will not continue with the rule if there is a subdomain(excluding www)?

 

RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_URI} !staging/$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ site.php?s=$1 [L]

 

basically url.com and www.url.com <-- rewrote, and no others...