Organizing Points

All

I've divided a set of X curves into N parts.  I want to then draw a curve through each Nth point ('N of curve 0' to 'N of curve 1' ... to 'N of curve X').  I've having trouble reorganizing the point collection to call the list items correctly, any help will be appreciated.  

Got it working once as shown (the one curve on the interior) with the slider delivering one of the set.  

Thx in advance.

DH