dxf imports to SW

Hi, I need to convert a Dxf file to SW as a part and then use it in a assembly. The problem isn't importing it into SW, but that the line in DXF file is then converted into curves, and then regular SW parts can't be mated to the "reference "part. I would like to know how to overcome this problem, as it is vital for the part be be lines for what i wnt to do.

Thanks,
Jacques jlerm@tricom1.co.za