Although I'm not too sure about international workers, I do know that it is possible to write the C of Q examination if you have a certain amount of experience (Sorry, I don't know the exact number of hours needed), this is known as Grandfathering. I have a feeling though that you will need to take an apprenticeship as I believe that your hours need to be accumulated while you are in Canada.
Check this link out, it should have most, if not all of the information you are looking for
http://www.citizenship.gov.on.ca/eng...chinists.shtml