How do you get a domain name with a provincial subdomain (i.e. xxx.qc.ca) ?

Answer 1

If you want something that's under .ca, then you need to talk to the people in charge of ca and ask them to register it:
http://www.cira.ca/

in the case of .qc.ca, it already exists, so to put domain names under that, you would go to:
https://domaines.riq.qc.ca/