OpenGL with OSG

Hi all,
I am new to both OpenGL and Open Scene Graph and am trying to find the easiest way to use what I do know. I want to open .flt files and add objects on top of these. OSG contains a .flt plug-in so this seems like a good start. If I use this, how can I draw OpenGL primitives with the OSG viewer? Alternatively, can I use the OSG plug-in with OpenGL?