Display a message when using Access restrictions meta box

The Access restrictions metabox is a great way to restrict access without having to put in the shortcode every single time on every single post or page, but how do I set up some kind of message saying either:

“You have to be logged in to view this content”

or

“This content is available to premium members, purchase membership or log in to view”

Because right now when someone is not logged in with the right membership/group it says that the page does not exist. which is both incorrect as well as confusing and unhelpful. even someone with the right membership would think it is a bad link instead of realizing he needs to log in.

Is there a way to display such a message without using the shortcode and just using the Access restrictions metabox?

Thanks

http://wordpress.org/plugins/groups/