Xander Bakker Suggested I Branch this off the original discussion
Basically what I am doing is I have a polyline that I apply a Start and Finish Z Value to an attribute via Xanders Python script he had written in my earlier topic.
But now I wish to introduce another feature class Polygon that intersects these Polylines at a static height part way through this PolyLine, and it derives it's own height from a user defined range similar to but not exactly at the same altitude as the underlying surface,
this in fact makes a section of the poly line the same height as that polygon over the area of that polygon
I will add some demo data to explain