MAGE is command line, same as MAME. You can use a MAME Frontend [such as EmuLoader], or could even write batch files for each game.
What you are supposed to do is navigate to the MAGE folder, then type :
MAGE xxxxxxxx where xxxxxxxx is the name of the game. From memory, Quintoon was
MAGE BFMQNTN [short for BFM Quintoon].
The names of the games are made to conform to the 8.3 filename format. There is a way of listing allowable game names, but I haven't clue how to do it. Something like MAGE /? in command line would be a good start.
To run it in command line mode, I recommend you sit the MAGE folder on the root of the drive [i.e C:MAGE] as it saves you all the hassle of jumping through huge foldernames and stuff.
To access a command prompt, go to RUN in the Start Menu, and type CMD