OK from reading the letter they enclosed with the CoPR you can only make an appointment and land at the local visa office as long as you have valid status in Canada, if your visa has expired you must go to the closet point of entry and land. This actually answers the question I was worried about if my passport was lost as I am only legal until Dec 19th. My CoPR is valid till April 10th, 2013 one year to date of my medicals. but if your passport expires before your medical then it will be the expiration date of your passport.