Assign roles to differend pages

Hi
Is it possible to assign  a role to a page?
What i mean is, i have a membership with a site map and each page in the site map only allows acces to a spefic role but i want to create and amin page that will allow
the admin to modify the menu that will be shown to the different users, basically something like this:
 Page1 --- > Roles 1,2 and 3
Page 2 ---- > roles 1,3,4
Page 3 ---- > roles 5,6
and etc.
and i want to be able to add the roles to the pages so that when my site loads and the treeview menu is populated from the site map, it will populate based on the user and the pages that are assigned to his role.
 Do i make any sense?

...