If the original designs were created in Autocad, you can open the file with Autocad and combine the line segments into a closed polyline with "0" line width. Then, export as DXF, import into Flexi, and most should come in grouped correctly. Some may require a few tweaks, but this is how I do it. Also, depending on what version of Flexi you are running, you may have to export the DXF file from Autocad as a Release 12 (lowest version you can export to). Also note that some spline segments exported as DXF don't play well with Flexi.