The BlackBox has GSX files in the aircraft folder /SimObjects/Aircraft/-YourBBSAircraft-/gsx.cfg --> Just put those in the virtuali folder.
If they already included a GSX.CFG file in the airplane main folder, there's no need to move it, because GSX will read it from there.
In fact, it would be best NOT move it, because a file in the main airplane folder, is read in "read-only" mode, because it's considered to have been made by the airplane developer so, if you want to further customize it, and make some kind of mistake, if you click the "Reset" button, you'll lose only YOUR customizations, not the ones made by the airplane developer, so you won't have to start from scratch.