A little fine-tuning question:
Do you want the vertical Polyline to be drawn always from the insertion point [what you would get from INSert Object Snap]? The accepted solution uses the DXF code 10 entry in entity data, which is the insertion point for Mtext, and for Left-justified Text. But if plain Text has any other justification, the insertion point is the DXF code 11 entry. The 10 entry is always the left end of the baseline, regardless of justification, which is also the insertion point only when Left-justified [in which case the 11 entry is always 0,0]. Is that something that you would want to account for, to use the actual insertion point and not always the left end of the baseline?
Also, I suggest preventing Object Snap causing problems:
(command "_.pline" "_non" pt "_non" (polar pt (/ pi 2) len) "")
Kent Cooper, AIA