Hi, Earl Osuagwu,,,
If you are using Paulmon board based on 89c51 MCU then all you have to do is to assign a port to the keyboard ,,,
I mean that you should connect the said lines(ie column and rows) directly to the 89c51 mcu,,
then you need only a code to scan the keypad on and off for any key pressed ,,and you also have to do it for upto atleast 50 times to rid of bounces from the keypad...
I can offer you the code that I write for one of my group of university final year students,, and it works fine ,,
I use the keypad scan up and forth and convert the scancode into ASCII code to display it on the LCD based on HD44780 controller..
I am offering you the full code including Hex to ASCII conversion utility...
All you have to do to mail me your Address and I will send it along to you,,,
thanks,,
M. Jawed