Yes you can, all you have to do is rename it like the emulator. Like if you have a config file that is zsnes.ini then you name the layout zsnes.lay and then the images the layout use, zsnes-art.png. And, you put this layout in the same directory as the others. I think this info is in the docs. This is for version 1.61, maybe it's different in 1.62 but I don't know I can't get it to run.