algorithmic modeling for Rhino

Curve attractor/repeller on Terrain Surface

Hi guys! I'm having some difficulties;

I am trying to make a definition that allows me to manipulate the surface of a terrain; which I obtained from sketchup google earth. I used the drape tool on rhino and used the resultant surface as a base from which I obtained a new surface with control points on grasshopper. Now I am trying to create an attractor/repeller curve that moves the control points on the Z axis acording to its distance to the point.

One of my questions is how do I split the points on the surface in a more efficient way?

I now there's a way to do it with "split branch" I just couldn't figure it out the path mapper equation. and instead I used the "divide list" and repeated the process.

My other question is where can I find some good examples on how to make a curve that attracts and repels the control points on a surface in the Z axis?

I am still kind of new at this (newwbeee) but I'm trying to figure it out by experimenting, reading discussions, and trying a couple of examples I see on this website.