Transparent Bordered Form?

Question

Hello, I was wondering if it is possible to have part of a form be transparent by putting a color there and setting that color to be the transparency key. I have tried doing just that but if I leave the FormBorderType to Sizable, it just makes the transparency key turn black and has a black border around the frame. I know I can fix it by removing the border and then adding dragging by some DLL imports but I'd prefer if I could leave the default border. Is this possible?

Thanks!