interpolating curves between the divided points of 3 curves.

I Have 3 curves AB, CD and EF. I have divided them into a set of points. now, i want to interpolate a set of curves through these points. sort of similar to tweening curves between AE and BF. how do i do it? can someone help me out?

here, i tried listing out all the divided points of the 3 curves to get a list of values to interpolate. but, if i try that, i am able to only list out the points of AB and CD. so, i used two lists to get divided points, first list of AB, CD and second of CD, EF. but, then, how do i join the list and interpolate the curves?