How can I export/import Camera data to/from Autodesk?

You can use WriteAutodeskParams.Viewport property to set the Viewport from which the camera data must be exported.

var wa = new WriteAutodesk(new WriteAutodeskParams(design1.Document) {Viewport = design1.ActiveViewport}, "out.dwg");
wa.DoWork();

After reading a file, you can set the camera data to a Viewport by calling readAutodesk.SetView() method.

ReadAutodesk ra = new ReadAutodesk("out.dwg");
ra.DoWork();
ra.AddTo(design1);
ra.SetView(design1.ActiveViewport);
design1.Invalidate();