If it is specialized enough, nobody will make one because they won't sell enough volume to justify the cost of R&D and production.
IF you can find someone good at wiring and making small things, you could get an appropriate plug, and splice the two types together after experimenting with the wires to see what connection(s) replicate the function of the remote shutter release, but it will be one of those "measure several times, cut once" jobs. Screw up and you will have nothing left over.