Midori

Hi, I just recently discovered Launchbox and I'm loving it, the interface is amazing and very beautiful, but I have a problem, the roms that I have for some consoles are in the goodmerge format, that is, there's a 7z file for each game and inside this file are all the versions of said game, the problem is when I run any of these games Launchbox just chooses automatically one of the roms inside the 7z file, is there a way for me to choose which file will be launched?