Yes. that is the wrong direction.
In the previous posts dannix got the true way.
forget navbuttons. That method is used to activate the builtin methods
if you want to use your own device to replace the standards buttons managed by MENWIZ and Buttons libraries (and declared with navButtons functions) you need to write your own function and to declare it to MENWIZ library using addUsrNav method.
The user defined function will replace the following internal one:.
In the manual there is a sample of the method to be replaced by your routine.
The trick is just be able to provide as return code one of the same codes the built in funzion returns.
The codea are the following literals:
// BUTTON CODES
// ----------------------------------------------------------------------
#define MW_BTNULL //null
#define MW_BTU //up
#define MW_BTD // down
#define MW_BTL //RIGTH
#define MW_BTR //LEFT
#define MW_BTE //ESCAPE
#define MW_BTC //CONFIRM
Look at the working code of dannix (your should be a little dfferent) using analog buttnos as you would like to. Be only careful: dannix simulate the forth button ESCAPE (he uses only 3 buttons!) , using a normal MENWIZ menu entry (with an action variable associated) to simulate it. Your code should be even simpler!