contour mapping problem

hi everybody,

I am trying to map a curved line at the exact position of a contour line onto a surface.

See image below.

I created the surface, the contour and the new contour curve but cant figure out how to get the curve onto the surface at the position of the original contour line.

the mapped new curve should ideally be a closed polyline which i could use later to split the surface with!

I have attached the gh definition.

Would be really great if someone could help me.

thank you for your support.