Unfortunately unless the hassy has a hotshoe I think you are out of luck - I had to buy a plusII to use it with my LF camera. The issue is that the ports on the flex, the one marked with a camera is for triggering a camera not for a camera to trigger a flash.
Try contacting PW, they may be able to help but I concluded it wasn't possible and bought a plusII.
I would be really thankful if you could supply a link to one of those pc to hotshoe cables. I am in the exact same situation and I want to get up and running asap. Is this what you are talking about?