How to hide or show the cursor in a window (not the console, but the program window)?

Question

C++ / C#

I tried to hide like this

ShowCursor(FALSE);
SetCursor(NULL);

And show like this

ShowCursor(TRUE);
HCURSOR hc = LoadCursor(NULL, IDC_ARROW);
SetCursor(hc);

But for some reason it doesn't work...
PS: I'm doing it from a DLL that I'm injecting into the program.
The program is a directx game.

Answer 1

www.sources.ru/msdn/howto/q131991.shtml