To include a configuration file in Apache is very easy to do. You simply need to update your httpd.conf to include that particular file(s).
To include the file photo.inc, add this line to your httpd.conf:
Include /apps/apache/conf/photo.inc
photo.inc contains a VirtualHost that looks like this:
ServerName myphotosite.com
ServerAlias *.myphotosite.com www.myphotosite.com
ProxyRequests Off
ProxyPreserveHost On
Allow from all
ProxyPass / http://www.test.com/phototest
ProxyPassReverse / http://www.test.com/phototest
Order allow,deny
Allow from all