You can't change the copygroup name.  It is always standard.  I'm confused
about the error you are getting.  Multiple copygroups can point at a single
pool without any problem, so the error you are reporting doesn't make
sense.  Also, remember that each component within a domain is distinct and
unique from a similarly named component in another domain.  For instance:

Standard copygroup in standard management class in standard policy set in
standard policy domain is different from standard copygroup in standard
management class in standard policy set in kelly domain.  You will see two
copygroups in the query copygroup command.  It is easy to confuse these
when using the pulldowns in the graphical interfaces to ADSM.  In fact, it
is easy to confuse these when looking at them in any interface.

Kelly Lipp
Storage Solutions Specialists, Inc.
lipp AT storsol DOT com
www.storsol.com
(719) 531-5926