

There was no code or command prompts involved. Initially, I thought the steps were intimidating, but found the process rather straight-forward in hindsight. Now, my laptop always boots to Catalina as always, but if I want to play COH-1, I hold the option key when turning on and the laptop and it boots to Mojave. The answer is basically to create a volume on the disk (NOT a separate partition) and install an earlier OS X such as Mojave on that volume. I have tested and implemented an Apple supported solution today in 2020 to continue playing Company of Heroes I for those who previously purchased the stand alone download through the App Store (NOT Steam), now that 32-bit support has ended with the introduction of OS X Catalina (10.15).
