Extract subsurf from double curved surface

[Balazs]

I am trying to extract a subsurface from a double curved surface defined by the intersection point of the surface and four lines. What do I do wrong?
SUBSURF DOUBLE CURVE SURFACE.gh (12.4 KB)

[inno]

I think you want to connect like this:

SUBSURF DOUBLE CURVE SURFACE_inno.gh (15.4 KB)

it was like this:

[Balazs]

Thank you!