To yuu:
I never took CGA. I only obtained some related CGA information when i made decision which designation i should pursue B/W CGA and CA 5 years ago. This morning, I called my classmate who is a CGA member of Ontario and work in Toronto. She gave the following opinions:
1, If you move to ON, you can enrol in Ontario CGA, transfer your credits in McGill then they will do the evaluation. If you still stay in Montreal, you can not enrol in ON
2, If you enrol in Ontario, You must take pace level courses, do assignments and write exams. If you enrol in Quebec, You need not take pace level courses and only write 2 pace level exams (Quebec can exempt 2 pace level courses but do not take this advantage if you hope transfer file to other provinces. Other provinces do not recognize Quebec rule. They will ask you to take the two exams again unless you can pass French to get membership in Quebec.
3, You need not any experience to write pace level exams.
To yuu:
What courses you already took in McGill and what province are you going to enrol. There are big differences B/W Quebec and other provinces in CGA programs. If you have no confidence to pass French language exams, You must follow the course list of CGA Canada. Otherwise, you will meet problems when you transfer file to other provinces. CGA need not experience when you take exams. Once you apply CGA designation, You need at least one year senior accoutant experience in Canada ( Ontario rule). In Quebec, two year accounting experiences is ok but you must pass French exam. All accounting courses you took in McGIll will be recognized by CGA. You can follow the courses list to finish all level 1-4 courses in McGill then transfer credit to write pace level exams in CGA.
The answer is no. CGA exam have nothing to do with the CPA exam.
Also, if you are not interested in US tax position or moving to U.S, I suggest you not to waste time and effort to pass the two exams, only CGA is enough.