I have gathered together a few instances of the Points2Circle and Points to Circle script for Cinems 4D from various places. Links to where they were found can be seen at the bottom of this readme.
Disclaimer: I did not write either the original COFFEE script version or the Python rewrite, credits belong to their respective authors.
The following article should help you understand how to use these scripts:
https://www.valkaari.com/?page_id=764
This seems to be a very useful script and many people are asking where to find it. They are currently being hosted on what seem to be non-permanent hosting solutions, so I decided this would be a better solution.
The original COFFEE script was written David Wickenden in 2007
The Python rewrite was written by C4DS and posted on C4DCafe