Custom Chat Rooms / Groups

I am currently running openfire with AD and also fastpath for some support stuff.

I would like to use the spark web or the web im client that comes with fastpath or something similar and use it in the following we for multiple websites.

Say I have a chat for website A, B, C

I want to be able to create a chat for website A and allow A to see all of the users that have logged into website A, same for B and C, keep them all seperate but allow them to see the users from their website. Is something like this possible by using anonymous logins like I pass a website ID into the chat page or something that it groups on.

Any ideas on how to accomplish this or where to look for something like this?

Thanks