How to deform an object (box) to create tunnels in it?

Hi, guys

I have already checked all the tutorials and other stuff I was able to find online and read "Generative Algorithms" book on GH. This forum is my last chance. I really need to finish this thing before Christmas.

I am gonna attach sketches of what i need to do just to make it clearer. Basically, what i need is take an object (say Box) and start deforming it to create tunnels in it.

The thing is that I am fairly new with grasshopper and not sure on the way how to do that. I have already experimented with attractors (in the opposite direction), tried to create point grid (although its not exactly what i need) and then move the points in a relationship with an attractor, but than I wasnt able to create a mesh. Whats more, i would have to change a topology of the mesh, even if i do create it.

Well, anyways, i ve already wasted a lot of time so any help would be nice. I m not asking for a finished script (although that would ve been cool:), just a hint on which direction should i go. Or which functions to use.

Thank you very much.