There is no option to handle this specific case actually.
There will be one in MadMapper 3.7.0. Please PM me and I'll send you a beta. You'll be able to specify "auto play settings" per column. So setting your main movie on column 1 with "play next column when movie reaches loop end" and setting your idle movie on column 2 with fix duration of 10000000 seconds, you could just map your IR sensor to trigger column 1. If you don't set the movie "restart" ON in the scene, it won't do anything if the start the column 1 multiple times, but it will restart if the movie assigned to your quad by this scene wasn't playing anywhere before (when coming back from "IDLE" scene where the "idle movie" was assigned to your quad)
Am I clear enough ?