That's the one, allright. you should use the latest version of AoC quick-starter.
There you can check an option named "full-screen windowed mode" or something like that.
Thing is, when using this, the game shows like it's full scren, BUT!
It doesn't really resize the window to fit the screen immediately, so the ingame UI will look weird and also the buttons won't be where you see them. kinda hard to explain, but whatever.
now, what you need to do is this: when the games has started, go to the video options, choose another resolution and press apply. when the game asks if oyu wanna keep the new settings, press "no".
Now your game is in "full-screen window mode".
Believe me on this. I've been doing this for a year :P