Canadian Helicopters flies the Air Ambulance contract for the Ontario Ministry of Health. Look up CDN791, 792, 793 794, 797, 798 and 799. Also search for them with an M at the end because sometimes they use it and other times they don’t. They also usually have a continuously renewed flight plan/squawk code (with the M) that gets entered into the system on a regular basis so that they are identified as soon as they show up on radar.
Typically a flight number will belong to the machine based in a certain city. That being said, the Toronto City Centre bird would be CDN799/CDN799M and the Sudbury bird seems to be 798.
Hope this helps.