Hello i have question. I need lisp to extract elevation in spots from polyline surface.
 
	I know for civil 3d and surfaces i work with this but for this project i need to make same thing in Autocad.
 
	 
 
	I know the math for interpolate but dont know how to make it. (dont have good idea for now)
 
	 
 
	Thank you all for support and help.  
 
test1.dwg