Assigning Admin mode on Conference Calls

We are using Asterisk as a MeetMe conference bridge only at this time not as our complete phone solution. We have users dial in via a PRI/toll free # and soon hope to bridge the Asterisk box with our Toshiba Strata system.

What I would like to do is have a way to assign control over conferences based on PIN but it looks like if the calls do not originate on an Asterisk extension that can be tagged as the Admin this can’t be done. Am I wrong?

Right now all users call the same 877 number, they are prompted for a conf room and PIN, the non Admins hit #.

The MOH works until the second user enters the room then event if the Admin isn’t present the conf starts and the users in the room are up and running. Since they all cone in on the same DID how can I set the config to differentiate between the users? I only have 10 DIDs and want to have mode than 10 conference room owners.