This is what I was trying to explain on Saturday night Deeno.
You need a plug (10 pin I assume) to fit the cable release socket on your Nikon and you need to cut this cable and interface it with a cable that is designed to work with DSLR Shutter or Images Plus and plugs into your USB.
A cable release such as this one.
The MC-30 - this is a strait up 10-pin release with a lock.
And then somehow cut and connect it to
this cable from OPT or equivalent cable.
This will then allow you to control the D200 via software.
It's as far as I can help because I'm not too familiar with Nikon, but hope it helps a bit.