Hi Truckian,
all you need is a variable resistor. It should have nearly 5 kOhms. This one you can use in a radio transmitter or in a infrared transmitter circiuit.
I don't know your special PS2 controler, but if it is an analog controler an the "axle-resistor" are 5 (or up to 10) kOhms, so it should work.
best regards
Thorsten
www.mikromodell.de