How creative are you looking to get? You can map one of the controller's buttons to be f1 and one to be enter, but I'm not sure if the driver station is smart enough to catch on to the fact that that input wouldn't be from a physical keyboard. The other option would be to do something crazy ala modifying
OpenFMS to recognize a controller button as an enable command.
It's not exactly what you're looking for, but would modifying that robot's code to have an "enable" and "disable" button work? That way you could leave your robot enabled via the DS (you still need a DS connected), but "disable" all robot functions (write all outputs as zero and ignore almost all inputs) until you "enable" the majority of your code via a button on your controller. Especially if you're using simple or iterative templates, that method wouldn't require more than an extra boolean, and an if/else statement.