resolve hostname outside my domain

[orak]

Hello!
I have the following problem in the following situation (little
simplified).

------------Internet------------
                           |
                           |        (external name: hhbgate.bonn.de)
                         Gateway
                           |        (internal name:
hhbgate.hhb.bonn.de)
                           |
                          --------------- local net, we use
hhb.bonn.de as domain name

on the gateway we use bind as dns.
Sometimes (not very often) the connection to the internet is down.
The following problem: internal user ask for http://hhbgate.bonnn.de/
If the internet-connection is up -> no problem
if the internet-connection is down -> no response
That ist not surprising but a problem to me. We use an e-learning
system named moodle which requires
a name of the site: we take hhbgate.bonn.de. So if our internet is
down we can't use moodle.

My question: is it possible to configure bind so that it resolves a
single name outside my domain.
I found only the hint that it is not possible to use an alias for a
name outside my domain.

It would be very nice if somebody could give me a hint. I search the
web an do "cross-reading"
in DNS und Bind (version bind 8, o'reilly) but I can't find something.

I hope my english is understandable, I use it not very often.

Thanks
           Karsten