Using a combination of M0 and block skip you could make kind of a menu.
Program stops with a measage "Do you want to do this?"
If operator does they make sure the block skip is on (to skip a goto around the jump to the "do this" code) and hit the green button. If not make sure the block skip is off and hit the green button to go to the next menu item.
Otherwise the only way to do any kind of input on the controls I have used is to edit the variables #100-#xxx and #500-#xxx