Create section - orientation by pick face

I’m trying to create wall elevations through dynamo. The way the graph works at the moment is by selecting all the walls, then drawing a line at the base of the wall (to set the extents and direction of the view) and also selecting the line.
I was hoping to make this possible by selecting the face of the wall instead of drawing and picking the line. I’ve had a go in the file attached but I’m having problems getting the direction of the vector correctly when picking the face.
Any help would be appreciated, thanks!

Create Section - Walls - Pick Line.dyn (39.0 KB)

By picking the face I mean having the section orientated to be looking at the face that was picked.

Solved now, if anyone wants to know for future.
I used the select point on face node. Then compared that point to the 2 end points of the wall to return which ever point is closest to the point picked. Now I know which is the start and the end points to give the correct vector direction

hi jimmy ,
can u please share your dynamo script which solves this , cause am trying to create a section by picking curtain wall .
thank u in advance .