Okay, so in order to Install and get Empire Earth II running in Crossover 23.0, you should first download the GOG.com Installer for the game. Now with the Installer file available, go and choose install. Select "Unlisted Application" instead of Empire Earth II, because the version has not been updated for the new version of Crossover yet. Now select the GOG.com installer and give a name for the Empire Earth II bottle. The new bottle for Empire Earth II should be a Windows 10, 64 bit bottle. Now proceed to install the new Bottle. When the installation is complete, exit the Installer, and the game and the expansion from GOG.com should be available to play.
This tip may prove no longer needed if and when the CrossTie for the Application is updated to install as a Windows 10 64 bit Bottle.