admin.php?page=custom_page

Is there a way to add custom admin pages to this? I am using a series of plugins that add various features and functions to the user admin dashboard – for example users are able to purchase ads from the backend of wordpress; or perhaps the fact I have a credit system with user admin pages that display current user credit count. I want to use your plugin to display these custom user admin pages on the frontend if possible.

http://wordpress.org/extend/plugins/wp-user-frontend/