arc through multiple points/curves?

hello guys,

i'm pretty new with grasshopper, unfortunately i'm using it for my final university exam, wich will be in the beginning of january :)

so i have this question, like you can see in the video below, it is possible to create an arc between 3 points on a curve. thats easy, but now i have no idea how to do it if you have multiple curves/points... for example 9, wich i want to use to create an arc. so how do i create an arc through multiple curvs/points?

thank you in advance

dmitrij

video link: http://vimeo.com/album/2282897/video/60604978