how to assign panel rotary controls to keyboard

[Demious]

I'm trying to assign rotary controls on the virtual aircraft panel to keys on my keyboard, but I cant find the right assignments in the key-edit list.
I'm looking for functions like increase/decrease radio frequencies, or increase/decrease heading adjust, in a way that one key-push, for example, increases the radio frequency by one step.

Seeing that like Saitek, with their radio control unit, has assigned a rotary button straight to the rotary button on the virtual panel, there must be a way to link those through the available commands within FSX.

Can anyone tell me where I can find those command?