Different results for the same lookup

Guys and gals,

I have a dilema that I am hoping someone has had in the past and can
offer some assistance. I have a need to setup my DNS structure so that
the results from a DNS lookup will differ depending on where the user is
located on the network. For example, if a user in Network A requests
abc.net.au (internal), the returned value is different to that of user B
in Network B also requesting acb.net.au from the same DNS
infrastructure.
Regards,

---------------------------------
Graham Trigge
Telstra Australia
IT Technical Specialist
Messaging Support, Northern Region
W +61 2 9201 9577
M +61 409 654 434

"Time flies like an arrow, but fruit flies like a banana"