Second-hand. That's an idea. And thanks for the link. I don't usually go for second-hand because I don't want the hassle of having to send something back if it is scratched etc., but a cable.
At least it is Nikon too. I'm sure HHargit above is correct. It is just making a circuit connect up so probably not going to break anything. But, psychologically, there is just something about a £2.00 release and my new Nikon which I can't quite bear.. I don't want to be the guinea pig proposed by poster gearsau.