help on pendant

I have a customer who wants a pendant for machine running cncpro.
he wants a single button to "run" or start a program that they will
repeat .
Any one do this using Cnc Pro? Seems like a challenge cause you have
to emulate the E and enter strokes usually required by Pro.
Here is the kicker,: I tried to talk him out of it,[no luck]Now I
have four days to get it accomplished.
HELP!

thanks
CB