Let's not beat around the bush: I want to cheat with XCom-Apocalypse. It should be no problem according to the internet cheat fora: Go to the main interface of Xcom, hold the ALT key and press "ufo cheat". The only problem is that pressing "o" (which is in "ufo cheat") opens the Xcom options screen. No matter, you say, because you have to press the ALT key with it, according to the cheat. Well, the ALT key is blatantly ignored by Xcom, which leads me to think that the ALT key is not delivered by DOSBox to the game.
I tried to make sense of the keymapper, but though all looks fine to me, it doesn't work. The keymapper says that "EVENT=key_lalt" and "BIND=Key left alt".
Does somebody have an idea about how to solve this?

Thanks a lot in advance!