Surface (or Rect) in surface

Hi all, 

Maybe already answered but unfortunately cannot find it. I am trying to create a GH definition where I want to connect a surface and i will get back a new surface within the boundaries of the first one. So far I can create the surface and move it within the boundaries (u,v values on the middpoint). What I want also is freedom to rotate also the new surface within the boundaries of the old one. When I rotate though I face two problems, first that when my new surface exceed the 45o angle then the local X and Y coordinates (so the width and depth of the new surface) are replacing each other. Second when I rotate the new surface the vertices of the new surface can go out of the boundaries of the old one. For the second problem I wrote a c# component that returns a new surface only when all the vertices are within the boundaries of the old one, but what I am aiming for is that the new surface remains always within the boundaries of the old one. I attach the definition and two screen shots for an overview! (

Any input would be of great help:)

Thanks a lot!

Best 

Tasos

P.S: Creating a new surface or a new rectangle is the same for me at this point - thus the title of the discussion - so it might be easier to create this definition with a new rectangle but I am not very familiar with it