Repairing holes in aluminum will be very tough. Considering that aluminum is one of the materials that dos not adhesive other material easy, that includes paints it will hold things in place but will not be strong by any means and you can't weld it like you would weld steal.
Anything that you would use to patch that hole will be held only by the inner walls of the hole and once you sanded to make it nice flash surface anything might knock that repair area off. This is going to be tough one.
I am always ready to try new things but I'm scratching my head to try figure out how this could be accomplished without wasting time and making big mess, I would love to know when you come up with something solid.