I am looking for Computer Games with the sophistication of Avalon Hill's 1914:

Such games exist. Quite a number of excellent war-games have been designed for the computer. Most have an AI (human vs computer player) option.

To download a completely free one, go to ssgus.com /ardennes-download.htm. There you'll find a game on the Battle of the Bulge which will probably remind you very much of the old Avalon Hill game (if you ever played it). It has pretty much the look and feel of a good, old-fashioned board wargame. (And it's distributed as freeware by the company that owns the rights to it, so there's no piracy issue to worry about.) You'll probably also find that your computer does make a pretty good opponent.

For more current and sophisticated wargames, try one of the following sites: http://www.shrapnelgames.com/ or http://www.hpssims.com/. Finally, if none of these sites have quite what you're looking for, go to http://www.consimworld.com/. This is a sort of Internet gathering place for wargamers of all interests. Browse this site, and you're sure to zero in on what you want.