I need to create a special role/user on my site.

Basically I want the users to log in with an username and password I provide without registering new accounts. It should work as a just multi-user role with specific permissions.

The problem is that anyone can log-in and modify the password. So, how can I lock the access to the user page even for the same user?

I'm looking for a small mod in order to add this option in the access control page. So I can lock the account properly.

-HRose / Abalieno