If button "A" and "B" is down button "C" will play frame "X"

Hi everyone!

I have a setup of five buttons, four choices and one “start” I want the possibility of multiple select

Example:
If I press button “A” and “B” + “Start” i end up at frame 6
If I press button “A” and “C” + “Start” i end up at frame 7
and so on…

Could someone please explain to me how this is done?

Thanx in advance!