RewriteEngine On

RewriteCond %{REQUEST_URI} !^index.php
RewriteRule ^([^/]+\.php)$ http://site.com/foo/index.php?page=$1 [R,L,QSA]

Query: 
http://site.com/foo/Services.php?


Result:

Not Found

The requested URL /foo/Services.php was not found on this server.
Apache/2.0.58 (Unix) Server at site.com Port 80