To better understand what is what, I reorganized 300ohm's NEC file and labeled each
functional sub-section...see 4nec2 file in my imageevent folder.
My 4nec2 file is a simple *.rtf rich-text-file (cuz imageevent doesn't allow *.txt files).
Once downloaded, save as a simple *.txt file and then truncate off "txt", leaving "*.nec".
Each straight wire is defined by a set of (X1, Y1, Z1) to (X2, Y2, Z2) coordinates:
GW No. #segs X1 Y1 Z1 X2 Y2 Z1 radius
#segs denotes the number of segments in each straight wire (a NEC thing)
radius denotes the radius of each wire
You might look at editing 4nec2 file so that it can be imported into CAD.
BTW: If you download the (FREE) 4nec2 program, it includes a Geometry Viewer
which can inspect the coordinates and other parameters for each wire: