If i'm right, the following may be something to play 'round of
Code:
Switch1 Var Byte ' let's say it's connected on PORTB<7:4>
Switch2 var Byte ' let's say it's connected on PORTA<4:0>
Result var byte

start:
    Switch1=PORTB>>4
    Switch2=PORTA & $0F
    Result=(Switch1*10)+Switch2