If you are a civil engineer or land surveyor, invest in AutoCAD Map 3D or use QGIS as your bridge. The hour spent learning MAPIMPORT or QGIS export will save you days of manually tracing screen captures from Google Earth.
After importing any KML into AutoCAD, always overlay it on a known georeferenced image or survey point to check alignment. Use the ALIGN command with two or three known control points if the conversion is slightly off. open kml file in autocad