need slave to tell a lie for app-server failover

[george young]

[bind-9.2.2, linux 2.4.19]
We are behind a corporate firewall, no access to outside dns,
a single flat inside dns zone managed by IT.  I have my own local
slave in case of crash or loss of connectivity to IT's dns servers.

In order to implement a failback for my app-server, I want to
be able to *locally* change the value of a cname from my primary
app-server hostname to the secondary app-server.  It's harmless if
my change propagates more widely, just unnecessary.  Since I don't
(and can't) have my own zone, I assume this is not quite kosher,
but it seems like what I need to do.  What sort of bind
configuration do I need to (slightly) locally change the zone
i'm ostensibly slaving for?

-- George