[App_rpt-users] Allstar 'Answering Machine'

My goal is to create a simple 'answering machine' for my allstar node. I would like for a user to be able to connect to my node and enter a DTMF command that would then cause the node to record the very next transmission and store it to a folder on a mounted volume on the PI. I have looked into using the built-in recording feature via *'**archivedir' *. Howver I am not sure how to control it so that it will start and stop recording. So my question is this. Is there a simple way to tell the node to record the next transmission, save it, and then stop recording? I am hoping this could be done via a script which could be called by app rpt via a dtmf command. Any info or suggestions would be greatly appreciated. 73, KM6TOA