663 is an internal number to the voicemail ... if switch 3 is on, and you transfer a call out of your Auto Attendant to it, the internal Modem should answer. So, you can dial in using your modem just like any voice call that's answered by the AA, then have your modem string pause x amount of seconds and then xfer to 663.
My Modem string in co-sessions would look like 9-555-1212,,,,,663.
9 to get out....555-1212 dials the main number that your AA answers .. the commas are 1/2 sec pauses or so ... 663 is like dialing an ext out of the AA.
Does that make sense??
