How can you format a PC computer game to run on a Mac?
I don't think that is possible. It is like putting a Playstation 3 game into a xBOX 360, or even a Nintendo 64 game into a Wii.
The only way to do it is to setup duel booting or a virtual drive on your Mac. To do this, follow this tutorial http://www.makeuseof.com/tag/virtualbox-running-windows-on-a-mac-for-free-sort-of/
I tried that but I need a different operating system for it to work and they can be expensive so thanks anyway, but that's why I wanted to do the whole format disc thing.
The only other thing is to Google the games name and see if they have created a version for Mac. Of course, you will have to buy it. If they don't have a Mac version, then there is no solution apart from getting Windows. They might have a game for Linux which is free Operating System?