Private category?

[elv]

Hi, I'd like to be able to show or hide a category depending on a user login/password.
I know frontend login isn't ready, but I thought I could use an external script for authentification/setting a session.

But even with sessions my real problem is : is it possible to tweak the menu to make it hide a category? I currently use the {NAV_LIST_ALL:x} replacament tag.

Thanks!