The launcher will try to run it regardless of what version you have, make sure you installed it in Company of Heroes Relaunched directory and not just in Company of Heroes folder. Also, make sure you have installed the Company of Heroes (new Steam version) from the library instead of the regular CoH.
Steam now handles the files, so it updates automatically and if you have an old versionof the file, you can check it by using the "verify integrity of game cache" in the local files tab on the properties of your game.
