Adding PolyLine to Existing OpenGL

Hi all,
I am trying to draw tracks into an existing 3D geometry using TPolyLine3D (because TVirtualGeoTrack is not supported in OpenGL). So my question is, how would I be able to add the tracks to the OpenGL?
I was also thinking…is it possible to add the tracks after drawing the geometry in OpenGL, or should I introduce the tracks as the nodes in the geometry and draw them altogether? or me being completely wrong.

Your help is greatly appreciated.

S.