It is going to depend on what fitting he has on the compressor. If it is a simple foster connection, then any fill system that you use on the tank would likely have a foster fitting on it too, and then a male to male adapter would allow it to fill.But it could be a different fitting, like a DIN or K style, depending on what it is set up to fill . . . .
David that would work perfect, all you'd need would be the double male foster hookup like whats in my photo at the bottom right.