How to create an area ontop of another area

[ViRi]

I am writing my own little video player, using
AxMicrosoft.MediaPlayer.Interop.AxWindowsMediaPlay er, and i want to add
stats when in fullscreen.

I am able to Draw to it with GDI+, but since there's a high framerate,
it flickers...

HWND = FindWindow("WindowsForms10.Window.8.app.0.378734a" ,
null);

HWND = FindWindowEx(HWND, 0, "ATL:0754F282", null);

HWND = FindWindowEx(HWND, 0, "WMPVideoWindow", null);

System.Drawing.Graphics g =
System.Drawing.Graphics.FromHwnd(new IntPtr(HWND));

g.FillRectangle(System.Drawing.Brushes.Red, 5, 5, 50, 50);

This example draws a 50x50 red square ontop of the Fullscreen video
window.

What i would like, is

to add a surface (label, whatever) ontop of this window,
find a way to draw flicker-free to it,
or directly inject the image into the Window via Subclassing.

If anyone could help me with any of these 3, please reply...

[ViRi]

Anyone?