Is it possible to render OpenGL-scene in Shadowwindow

Hy there and thanks for any help you can give me,

i have created a window with an OpenGl-main scene. Afterwards i initalized a
shadow subwindow into it where i want to draw a menu in order to manipulate the
main scene.
I know how to put bitmaps into the shadowwindow but not how or if i can render
an interactive menu written in OpenGL into that very shadowwindow.

Any little help would be very appreciated.

Bye, Ralph