dont apply normal redirect rule if call is from a specific subdomain

I have a subdomain which is added as a serverAlias to 开发者_JAVA技巧the main domain. I am using this subdomain only for static content such as images and js, so I dont want the subdomain to follow rewrite rules and load index.php if a file is not found, I want it to show generic 404 page which is default from the server

I wanted not to apply the rule for my subdomain, this code worked for me

modifying bradym's block as example

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{HTTP_HOST} !^static.example.com$ [NC]
RewriteRule (.*) - [R=404,L]

Something like this should work:

RewriteEngine On
RewriteCond %{HTTP_HOST} static.example.com
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule (.*) - [R=404,L]