A picture is worth a thousand words indeed, Sol 
I think what you’re aiming for is the following handkerchief surface:
Multi-line comments seems to be a tad buggy. Also, I think I need to work on my commenting skills.
Mehmet, you’ve taken DS lacing to a new level! You’ve managed to define a complex parametric surface in just three lines of code! It’s extremely compact. I love it.
Awesome gentlemen! Many thanks. Very cool stuff and exactly what I was after. Not to mention I learnt a hell of a lot in the process.
If anyone’s still curious about this thread, I solved the problem in a slightly different manner.
The little bit missing from the definition is simply me populating Revit with a very basic family (Type ‘radius’ of equal width and length, height defined by curve length).
