GPS Car Accessories

I have recently come to sell my PDA (Orange M600/HTC Prophet). I used to use it as a GPS in the car and as a phone until I got a new one about 8 months ago.

The problem is, the GPS device connects to the phone in an unusual way. I have the PDA car holder which acts as a charger and a bluetooth device. The GPS unit (UT-41), then plugs into the car holder via a port that looks like a modem cable. The PDA holder is then Bluetooth, which you would connect to the phone using the pairing facility just like using a bluetooth GPS receiver or headphone etc. But unfortunately, due to the length of time since last pairing I have just totally forgot the pairing code, and due to the PDA not being switched on for a while, it reset itself when I charged it back up. I can not find the code anywhere and have tried all usual codes that I can think of/ find on the internet. Is there anyway I can reset or somehow get the code back using a piece of software?

Thanks in advance!