My mod_rewrite code is:
Options +FollowSymLinks
Options +Indexes
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
Rewrite
The server won't ever know whtether the request came via relative or absolute path so there is nothing You can do about it. As stated in another answer, You could make exceptions but maintaining all of them etc will become PITA at some point. ;)
I always use absolute paths especially when rewriting so I'd suggest just that, it's the easiest way