PLacing a billboard in C++

Greetings Fellows of Oculus Dev and congratulations on a well - done SDK released . the C++ samples compile and execute falwlessly, which is great.

Now for my question : I took the simple room example , and wanted to place a billboard , 5 units away from the camera , so that any camera position change will have the center of the billboard follow the camera LOS , but will react to an orientation change. is there any way to do that ?

The idea is that whenever the user presses the "Space" key , this billboard will immediately appear in front of the USer's LOS , dead center. and the user will be able to change orientation inside the billboard, but not move as the billboard will be always "Stuck" in a particular offset in front of the user and traverse the room with the user.

In addition , is there any example of a collision detection of the LOS and my billboard in OpenGL ?

Thank you .