Ability to use keyboard.h or another library to keypress num pad on keyboard

I have an adafruit flora and I'm creating a PC game controller out of cardboard and conductive paint using capacitive touch. I am using a retro game emulator to play the games and I want to stick to the default key mapping for the emulator. The "player one" controller is complete and it works well using the standard arrow keys and left control, left alt, left window, and keys z and x. I'm using the keyboard.h library.

For Player 2 which will be a different flora plugged into the same computer, the emulator calls for the arrow keys on the keypad of the keyboard. I understand pressing a key on the keypad sends a different hex value than pressing the corresponding key on the keyboard. I am confused about the hex value key mapping in keyboard.h because the values don't match up with virtual key codes from microsofts website or ASCII keyboard hex value standard.

Is there a library that includes keypresses on the keypad built into a keyboard? If no library is available, how are the hex values in keyboard.h derived so I can possibly create my own?

Thanks much,

I have usually solved such Problems using the following technique:

Write your program to use the "known" values. When a keypress is detected that is NOT one of the known values, you Display it to the Screen (lcd Monitor, Serial Monitor, whatever). You could Display it as a hex value or as a simple integer (easier). Write down for example that when you press key x, you get value v. This allows you to complete your list of "known values" and you complete your programming and remove the part for displaying unknown keypresses.

You wouldn't really have to update Keyboard.h. You could use the reported values (as above) directly and use the comment to explain what key it is, define your own constants in the program, etc.

Awesome technique, thank you!