IFF you can get a proper schematic circuit diagram for both systems' hotshoes and flashguns, it may be possible to make an adaptor, IF the trigger voltages won't fry the electronics of your camera. Personally, I would try to do it using something like Pocket Wizards but I would check with the manufacturers or importers that such a ruse would work before spending! Probably cheaper to sell your Sony flash and buy a Canon one.