How to filter pages in backend according to custom variable?

Hi,
I have a multisite network, and in every blog backend, I can see many admin messages I don't want the users to see.
I have some custom variable in pages that tells the system that this post is designated as special.
Can I show the user only pages that are designated as special in backend "wp-admin/edit.php?post_type=page" page? Using some query in the URL maybe?
Thanks