Hmm...I wonder how you could simulate the long, stagnant Western front without having some sort of zone of control arrangement. In Civ4, the way the warfare mechanics work, I'd assume units on both sides would just shuffle right past fortified machine guns and go straight to the cities without batting an eye. Of course, then you'd have machine guns guarding the cities (with only infantry, cavalry, and artillery for attack...difficult (of course, tanks would come into play soon thereafter and lead to a dynamic shift in the war, as in real life), meaning that I guess the "front" would take shape along a string of smaller-ish cities in northeast France. Which I guess is not all that historically inaccurate. Granted, with the awesome offensive stack defense of the machine guns and without anything to really counter them before tanks, the attackers could keep on marching past the fortified border cities straight into Germany and/or France...but there they'd actually face the same problem of actually taking the cities there too. With Civ4 warfare being so city-centric, you might get some slightly different scenarios developing, but it would still be interesting.
But as to the original question: alas, I know not. Would be fun, though. Gallipoli, Tannenberg, Russia's Caucasus campaign, Britain's middle-eastern campaign (with maybe a great spy or great general playing the part of Lawrence of Arabia)...you'd have to use an earthmap for sure to capture all of this fun. Also, the icing on the cake would be if you could program certain events to happen, such as Russia suddenly changing its civics at some point and signing peace with the Central Powers, but only once Russia has lost x% of territory or something.
And considering that, historically, WWI and WWII are basically the same war with a small interlude in between (lots of historical reasons for looking at it like that), it would be interesting to be able to keep playing on and see if the simmering hatred of the German leader would precipitate another outbreak of war once Germany had gotten better techs and re-formed a few SoD. (And the AI would have simmering hatred of France and Russia especially...there's the "You brought in a war ally against us!" penalty that would apply. Also, close border tensions. Also, you could put in "You declared war on us!", as that's how Germany might see it, regardless of the actual complicated mechanics of how the war started (you'd probably have Austria-Hungary and Germany in a defensive pact, Serbia in a defensive pact with Russia, Russia in a defensive pact with France, France in a defensive pact with England, England in a defensive pact with Belgium...jeez, just imagine all the war horns going off at once! I guess technically the game would compute Austria-Hungary as having declared war on all of Serbia's allies down the line (you could even program in a game event triggering insta-war between the two, kind of like the what's-it-called espionage one that already exists), and the Austria-Hungary defensive pact with Germany would terminate, but then Germany would jump in anyways, meaning it would technically have declared war...meanwhile, the Ottoman Empire, Italy, and the U.S. would be either dogpilers or bribed allies. Germany's relations with the U.S. would get a diplo hit from "You declared war on us!" Boy, this is confusing, even in Civ terms (in real life, the start of WWI was even far more complicated, of course.)
