C++ sends virtual key with WM_KEYDOWN on keybd_event()

I would like my program to send this third party virtual key VK_ALOGIN or 0xf7 with WM_KEYDOWN. The reason I want to send with WM_KEYDOWN so the program that receives the keyboard message knows it is a virtual key.

So I try the following:

keybd_event(0xf7, 0, 0, 0);

But the program that receives this keyboard message, it receives WM_CHAR instead of WM_KEYDOWN. So is it possible that I can send 0xf7 with WM_KEYDOWN?