[Zope] Changing file ownership

[Eric Shuman]

Using an external python method I am trying to change the group ownership 
of a directory on a Red Hat 6 server.

Here is the line of code in question:

os.system('chgrp -R extranet /web/htdocs/clients/test')

When run from the command line it works fine or if run as a python program 
from the command line it works fine, but if run as an external method it 
doesn't work. An "Operation not permitted" error occurs if I try to do the 
same thing using the os.chown(path, UID, GID) command in the external 
method. I'm assuming it has something to do with the permissions that 
Zope/Python is running under. (user:nobody)  Any suggestions or insights 
about how to accomplish this task from an external method?

Thanks,

Eric