I am proposing an application using my ip office 412 and voice mail pro where a message plays over an intercom. The idea is, I have a prerecorded message with evacuation instructions that users can "activate" from any phone in the event of an emergency, dial a predetermined shortcode(?) and the message plays. Sounds simple to me but I can't figure it out. I have also tried to play the wav file over the phone's speaker but the closest I can get is an "Invite" that activates the file when I accept (or pick up). Any ideas / solutions?