It kinda sounds like you want to adjust what the server uses to generate REST URLs, ie: briefcase, document, calendar sharing etc.
Say it's generating a URL like http:// server1.domain.com and you'd rather have it http:// mail.domain.com:
As long as 'mail' has a proper DNS entry to point at 'server1' both internally and externally. In 5.0.9+ REST URL's are composed of 3 attributes: zimbraPublicService[Protocol + Hostname + Port] to avoid dependency on zimbraServer objects.
zmprov md domain.com zimbraPublicServiceHostname mail.domain.com