Lofting between two curves, but only 'half-way'

Hi

I've got a problem that hopefully has an easy solution - please see the attached image.

I've got two curves, shown as orange and pink. The orange curve is quite long, and part-way along it I have a point that's the first point of the pink curve. I want to loft between these two curves, but when I do, it obviously lofts between the whole length of the two curves, rather than just the part of the orange curve 'after' that pink point.

I hope I've explained that well.... Any help would be much appreciated!

James