Form com um furo que deixa ver atraz

Var
Region, Region2 : hrgn;
begin
Form1.FormStyle:= fsStayOnTop;
Region := CreaterectRgn(0,0,width,height);
Region2 := CreateEllipticRgn(30,30,100,100);
CombineRgn(region, region, region2, RGN_DIFF);
SetWindowRgn(handle, region, true);
end;