Add a general controls description

[Stormrider]

I'd like to add a joy button to MaLa to display a custom image with some controls descriptions. This image is always the same (generic), not depending on the selected game. I've manage to do so with CPV2, using controller/keyboard/external application/ and defyning a new appz with a keyboard key running CPV2.exe -b=mameuih.jpg. Problems: this only admits keyboard, not joystick. Also, that will only be valid for horizontal orientation, because I need another image for vertical orientation. There's support in MaLa for Control Panel Viewer, but... only for when I launch games or as a substitution of the info panel??? Maybe CPV2 can be configured to define a joystick button to launch it? I don't know, because it's the first time I deal with this program. Also, does it support dual orientation? Actually, I can fix all this by creating an Autohotkey script which remaps defines a hotkey for the joystick button which runs CPV2.exe -b=mameuiH.jpg when in horizontal mode and CPV2.exe -b=mameuiV.jpg when in vertical mode (getting the info from selection.ini), but is there a better way to do what I intend to do?