Adding users in the Network to ASP.NET Membership Roles?

I am creating windows authentication page for my MVC website. This is for a customer service department where users are on the Network.
Members to the Network is added by Network Administrator.
Members in the Website is added by Website Administrator.
Website has ASP.NET Membership roles like -
Customer Service Team,
Customer Service Manager,
 Project Manager and
Service Manager.
Website Administrator should be able to assign each user on the network to one of the above user roles on the website. I am creating a Website Administrator area where Website Administrator should see the each Network User and assign him/her to a user role. How can the Website Administrator access the Network Users created by Network Administrator and assign each of them to the User Roles within the W ...