There are no RTW desks in Auckland -- or Tokyo. Most CTO's have little or no idea when it comes to RTW ticketing. They need to pass the request along to their RTW operations.

Decide what airline you want to ticket on (AA, QF, CX, BA,...)and contact them locally in TYO or in AKL or in their home country (US, Australia, Hong Kong, UK). Doing the latter might get you connected to their RTW operation.

I'd probably try TYO first as it is local for you. Tell them you want to originate a OWE RTW ticket with them, buying the ticket in New Zealand. See if they will book your itinerary and pass it to their fare desk for pricing. Be sure to emphasize that you will be originating in NZ and buying your ticket in NZ (this has a major impact on the price you will pay).

If that doesn't work then I'd try the NZ office for the airline you will ticket with. Generally, the airline with the first international segment or most of the long haul segments will be most amenable to helping you and ticketing you.

BTW, the comment I made previously about locking in your first international flight doesn't apply for originations in NZ. You can change things up to an hour before flight time. Of course, this may still require a ticket reissue and a recomputing of the fare and taxes which could take days to do.