Creating Default roles for menu items based on category.

I'm using drupal 5.7 with the "menu per role" module installed. I have several categories call them CAT1 CAT2 CAT3...

For CAT1 if I create a new piece of content I want to be able to tell it that it is a child of menu item Cat1 so all of the stories I create for CAT1 appear in the sidebar as children of the Cat1 Menu Item.

The problem is for CAT2 I want the stories to appear under the sidebar menu item Cat2, but only if the user's role is 'anonymous'. I know that I can go to /admin/build/menu and using "menu per role" select this to appear only to 'anonymous' users which is what I'm doing now.

I need to hand this project over to someone much less technically inclined and I don't think that they will be able to remember to change the permissions on the menu item.

So the long and the long of it is...

Is there a way I can specify that for CAT2 any story created, when the menu item is created, automatically add (mid='$nid', rid='1') to the menu_per_role table in the database?

Bare in mind, I don't want to this change happen for any stories created, only ones for specific categories.