Part Cross-Section in Sketch

I have not figured out a way to get a cross-section of a part's geometry onto a sketch so that I can then use it to create subsequent features. Hopefully the attached screenshots help to illustrate what I want to do.

My goal is to get the blue sketch line shown around the truncated cone in the first image driven from the model geometry. I have artificially created it for these images. The plane shown is a datum plane offset from the plane that is used to set the top of the cone.

This is the VIEW cross-section shown on the plane. This is the the circle that I want to sketch and have driven by the conical feature. If the diameter of the cone changes, or the position of the cone moves, I want the driven sketch to update accordingly.