Perhaps somthing like this will do what you want.
Code:
getword:
    value = 0 
    for x = 0 to 3
        Gosub getkey                  ' Get a key from the keypad  
        lcdout I,Line2 + x,#key     ' Display ASCII key number
        SELECT CASE x               
           CASE 0 
              value = value + (key * 1000)
           CASE 1 
              value = value + (key * 100)
           CASE 2 
              value = value + (key * 10)
           CASE 3 
              value = value + key
        END SELECT
    next
    return