Or even easier - make a default folder to which DOSBox mounts automatically.
Upon instalation you have to choose where you want to install DOSBox anyway. How about if intalation creats a DOSGAMES folder on the same drive?
All that would be needed then is to say that every game should simply be placed in that folder and that's it.
On the subject, I've just made something like DOSBox for dummies and sent it to Data (our contact with the DOSBox developing team - I think he has quite a lot of influence on the DOSBox project) trying to cover the most basic steps to run games with DOSBox.
DOSBox for (gamer) dummies