Request add a additional feature to a lisp

[smallƑish]

I have a lisp (D2E.LSP) that makes double elbow for the HVAC duct. can help me add VCD by automating it? A basic idea LISP is attached (vcd idea. lsp). A sample drawing is attached for understanding.

And D2E its working gif file also added.

[Sea-Haven]

If you look at your other post I suggested a drag over for the selection of line work could apply here. The only issue is the created order of lines needs to be checked so the pick 6 points is reflected. This can be done taking the start point and comparing the distance to each object and sorting the entities based on this. May jump to this post as you have the lisp to draw correct answer just want simple pick method.

[smallƑish]

Yes, I realized the same. But facing difficulties in substituting the values for the points to execute the same. Cant find whats the error. 

[smallƑish]

How can I find out the Block insertion points? As it's passing through complicated sub functions.?

[Sea-Haven]

You need to plot out an answer, then do a dumb thing like LINE !pt1 !pt2 a line should appear mark on your sheet where these points are, keep going !pt3 !pt4 Enter, some of your other points have obscure names. 

(setq pos: (inters en3:p1 en3:p2 en2:p1 en2:p2) pos is where 2 lines would intersect. Again do LINE !en3:p1 en3:p2 Enter

NOTE THE USE OF ! implies a lisp variable.