Not sure if there is any thing like what I’m about to say, but some routes are made from companies. For example let’s say you are flying from CYYZ to LFPG. There is a company route for the 777 for that flight. CYYZLFPG01. Just to make it more realistic, add this.
You can just search on this website (flightaware.com) and it will give you everything you want to know about the real route (eg Cruising altitude, speed, aircraft and so on£