You said backup, did you mean a full incremental once a month?
If so, the easiest way to do that is create a second node and second stanza
in your dsm.sys for the server with a different policy domain/management
class and use the -se option with a private dsm.opt for your include/exclude
list.  Mark the copygroup with mode=absolute.  Use a separate storage pool
if you would like to send just those offsite.

Paul D. Seay, Jr.
Technical Specialist
Naptheon, INC
757-688-8180