You can use some 1/2 inch plywood and build a briefcase style box for it, just mount it to the wall of the briefcase. I personally wouldnt even put a front on it, just the back wall, a bottom, two sides, and the top where you can put the handle. I am not sure of the dimensions exactly, but I would think it would be around 18 inches wide by 18 inches high by 8 inches wide. Maybe even offset the handle toward the back wall for extra support and to keep the box further away from your leg when you walk. I Hope this makes sense.