Our FAQ for SEPSBE reflects the following:
Can an internal LUA server be configured to provide definitions to the SPC?
No. SPC can only receive updates from Symantec's LiveUpdate servers.
If you would like to review the entire FAQ you may follow this URL:
http://www.symantec.com/business/support/index?page=content&id=TECH96135&locale=en_US
Regards.