Videopac map 1,2 into controller buttons

[Pyjamarama]

In the VideoPac emulator lr-o2em, I want to map the numbers 1,2 into controller buttons.
I opened up RetroArch Controls section but it has no option to map them.

[sausage_toes]

I was trying to map 0 and 1 to the l2 and r2 bumpers.

I added these lines to /opt/retropie/configs/videopac/retroarch.cfg above the inclue:

input_player1_l2 = "num0"
input_player1_r2 = "num1"

and tried going into the emulator's "Quick Menu / Controls" by pressing Start + X

and no luck.

There is just no option for anything other than direction and fire. the retroarch.cfg changes I can see in the menu, but don't actually work to select a game