I think you already gave me some help on my own topic
For people following here, I am using a Rocktek G2 android box, the retroarch that Launchbox downloads automatically doea jot work on that device. I downloaded from Reteoarch website the 32bit android APK, and this one works. Now I need to make Launchbox to see this instalation and Faeran pointed out that I can manually set the emulator I need on the extra options for each system.