Im fairly sure that I used one of the Ipac mame boards for my joystick controller. I think this was a plug and play job as the pc recongised the pcb as a controller when plugged in to the usb port and all the key mapping is already programmed into the mame pcb. What you need to do is wire your buttons/switches to the correct inputs marked on the mame pcb and they should emulate the control of the keyboard keys.
I will have a look tonight when I get home and see if I can find any documentation for it.