I know this video is centered around EB's Trivial Script software, but that piece of software is directly related to the most important settings of the game, and if you installed Rome using the CDs then it can also run your game for you. It was not programmed to run EB if Rome was bought using Steam, but that is not a matter. If you view the video, and read the video description, you will notice that the simple creation of one shortcut and the editing of that shortcut's parameters will allow you to run EB even if Rome was bought through Steam (I promise it works, because I myself bought Rome through Steam).