Hi Rob
I have just gone through the same exercise with my EM-200 Temma 2M mount. It is a special connector. I got onto Peter Tan in Hong Kong and got him to make my AG cable, mine went straight into a QHY-5.
http://www.tan14.com/Tak.htm bottom of the page.
He can be a bit difficult to get onto, I am awaiting a reply for a longer 2M to Serial cable.
My AG cable only cost around $20.00 from memory.
Cheers