Summit 800. I want to be able to dial a DID to access voicemail so I can press * or # and retrieve messages from multiple mailboxes.

You could have the did ring to a bogus ext or slt phone and set it to preset fwd imediately to vm. then just record the vm greeting to say press pound to check your messages. once they hit pound it will promt for ext # and password. make sure you add a station authorazation code (password) for every one you need remote accesss. even if you set the vm box to no password, you will have to use one to remote access.