Pulling points on surface with attractor

Hi everyone! 

I'm having a lot of trouble with what I think is a fairly simple thing to do, but seeing as I'm relatively new to grasshopper I can't seem to find a way to do this. 

What I'm trying to do is generate a 3d surface based on the image in the grasshopper file, where black areas are highest and white areas are lowest. This is done and the surface appears, but where I'm having trouble is when I try to move these points around, seeing as I want them to follow specific curve paths. 

What I think needs to be done is pulling the points towards the curves and  using these to create new points that follow this path.. 

I don't know if that makes any sense to anyone? Can somebody help me out please? :) 

Happy Friday to all!