UCMA change status of any user

I started a thread over here: http://social.msdn.microsoft.com/Forums/en-US/communicationsserversdk/thread/0fdfe384-cac9-479b-9373-b077f50d1343

About how to update the presence of a Lync user programmatically.  I've gotten that accomplished but when I authenticate the UserEndpoint I have to use the credentials of the user I want to modify the status of.  For the purposes of this project that isn't feasible, I need to just be able to specify one admin account and allow that to change the status of any user.  How can I do that?

I've set up my development box as a trusted pool in Lync and added an application endpoint, that doesn't seem to have helped.

Thanks,

Todd