STEP visualization

Please Help,

I am trying to build a simple visualizer using OpenGL that is built off of a STEP (.stp) file. I want to start small and build from there but I can seem to find no information on where to start. I am building this for a Windows XP platform. All I want is to visualize a simple line geometry.

Has anyone out there done this before? If so some simple intro code would be great. maybe to visualize a small .stp file?

Thanks in advance for any help/hints.