Making a polysurface out of two hexagons

Hello,

I've been messing around with Grasshopper for the past couple days, trying to design a somewhat 'nice' house within a few weeks. This is especially for learning purposes.

So now I got this bunch of 'crystals' (which don't look very much like crystals because of the limitations in the design exercise), all made out of two hexagons above each other connected by lines. I've made this with hexagonal grids of 1x1, followed by 'divide curve' and lines that connect between the upper and the lower points.

What I want to do now is make a polysurface/brep out of this within Grasshopper, because I've got all these sliders that I'd like to still be able to adjust as the model changes real-time. (In fact, I can't even get it to work within Rhino itself :$)

I've literally got no idea how to tackle this. I've tried to do it via multiple four-corner surfaces and lots of other stuff as well, but I really lack the experience to really be able to think of some useful things.

Oh, and while I'm at it: I would like to be able to 'subtract' most of the inside of this massive 'block' so that I've got some sort of shell in which I can design the interior and inner walls and so on. I haven't got a clue as to how to do this either :')

So yeah... Thanks in advance for anyone helping me! I'm really about a total beginner when it comes to Grasshopper, so learning how to do (hopefully) 'small' things like this within this extraordinary software is all an awesome learning experience. 

Jiri Swen