1. search on here / read the Transport Canada web site, eg:
Advisory Circular (AC) No. 400-003 - Transport Canada
Likely you can only do one of two things - get a private licence based on your SAA commercial if you meet the hours breakdown ( eg night hours / night training is the usual gotcha) or get a validation of your commerical if you fly for an operator. You can then convert the 'based on private' to a commercial by meeting the hours and training requirements and doing the written/flight test. You can use a good chunk of your existing training as long as your logbook is signed/stamped. In other words - you'll have to work at it. On the plus side you can walk into a TC office and discuss it all at the counter with a helpful person.
2. Forget it/marry a canadian/get a day job. What altiplano wrote.