There is, but generally speaking there are no special dispensations for having a RIBA (or any other non-North American) accredited qualification. The details vary from province to province, but you'd be looking to enroll in the Intern Architect program within the professional body for your destination province.
The first step for a foreign-trained architect is to get your degree recognised by the CACB - no mean feat, as it's essentially down to the applicant to demonstrate how their architectural education meets an equivalent standard to the Canadian syllabus. This includes providing a detailed description of all courses completed as part of your degree and a portfolio of studio design work. It's not impossible but it's a pretty onerous task (as I'm discovering myself). If you're a relatively recent grad it should be a little easier - I graduated nearly ten years ago and a lot of the information the CACB are looking for doesn't seem to have been kept by my school.http://cacb.ca/index.cfm?Voir=sections_liste&Id=2790&M=1358&Sequence_No=2790&Niveau=2&Repertoire_No=660386109
Once you've enrolled as an Intern Architect, you select a mentor, log hours and sit a series of exams (ARE). Then you gets to pay your fees and add letters to your name. It's worth noting that you don't need to be a registered architect to work for a firm in Canada, but you can't call yourself an architect or practice solo, with some exceptions for particular kinds and sizes of project.