Conceptual Mass creation with Dynamo

I am thinking of using Dynamo to create a Conceptual Mass. However, I am stumped from the very beginning. Please lend me your help.

I am planning to create the following flow.
(1) Draw a Geometry that shows a cross-section in Dynamo and export it as a family.
(2) Create a Palne by dividing the line segment that shows the Path and generating coordinates.
(3) Insert the cross section of (1) into the Plane created in (2) and create Conceptual Mass.

First of all, please tell me about this (1).
How can I register a Geometry drawn in Dynamo as a cross-section?

A closed loop of lines in a family created from an an adaptive component family template should do the trick - just like you would do with the UI. You can also generate these as standalone lines in many cases, though you’d loose downstream parametric control.