Refine your explode command and add this
defun Bang (str)
(setq sapi (vlax-create-object "Sapi.SpVoice"))
(vlax-invoke sapi "Speak" str 0)
(Bang "BANG ")
I tried extracting the contours, but it does not accomplish what I need. I use Civil 3D 2013 and I sent my drawing (with surface contours) to someone using Carlson 2013. My contours were not visible. When I extracted them and sent it they could not open the drawing at all. I had to completely explode the surface and then I lost my labels. Even though the resultant polylines maintained their elevation, I was unable to label the polys with elevations.
Did you try using the Export To AutoCAD commands? This may be the best way to send the surface.