center of mass MSD

Dear MS users, it is me once again,
Do you have any experience (or any script) calculating MSD of center of mass of polymer chains?
I know that is possible to calculate centroids but in MS is not possible to calculate the MSD of these centroids. So, Do you think that would be posible to write a MSscript in order to get this com MSD?


As usual thank you very much for reading this email and for your ideas.

JAvier