Configuring an NCR Dyna-Key Monitor (Key Assingment)

I have installed RMS on a NCR Cash Register,with a NCR dyna-key monitor (5953 -3090). The Dyna-Key buttons on the monitor along side the screen automatically corresponded to the F1- F8 function keys in RMS, other buttons corresponded to a few Shift + function buttons in RMS, i want to be able to assign the buttons on the monitor with RMS function buttons that i choose, more over the client wants to be able to change the key assignment at any time he wants for cases such as if a key malfunctioned he wants to be able to re assign the function to another key. he used to do it on the NCR software (Scan master). if anyone can help i need this urgently.