Adding automatically and sequentially values to z axis of contour lines, polylines.

Dear Autocad Experts,

My name is Apu, I just found in the webb CADTUTOR your email address, and I was wondering perhaps you can help on the following question.

I have a topographic map in 2D (x, y and all values of z are equal to zero), but every contour line has text label elevation for every contour line; every contour line is a polyline.

I would like to add sequentially and automatically the elevation value for every z axis of every contour line, is there any way to do in autocad 2016?

Your advice and time are much appreciated.

Thanks in advance,

Apu

YEs and No various ways to solve the problem. the best way is go back to who created and get a 3D face file of the project. IF the plines had a z then easy no real auto way to assign z to pline some will get correct others may be wrong.