There are plenty of stores in Australia running WPN events. Any store which runs official Magic: the Gathering tournaments should have a membership number to give you.
If you go here:
Store & Event Locator - Wizards of the Coast then click 'Play' and select everything except 'Other D&D events' and 'Other Products' then the listed locations are all likely to be able to help you to get a DCI/RPGA number. Once you have one, you can follow the instructions here:
Dungeons & Dragons Home (Private) Play to activate your private play co-ordinator status. Once that's set up you can use the 'Event Sanctioning' link at
http://webapp.wizards.com/personal.aspx to create a private event and select adventures for it, the 'My Events' link to download the adventures (choose the event, then scroll to the bottom and you'll find a download link), and then report (or cancel) the event using 'Event Reporting'. To report it, all your players will need DCI numbers.
The current plan is to remove private Living Forgotten Realms play from the WPN system altogether, but the LFR admins have to wait until the WotC community site can host the adventures for download before that change can be made, so in this transition period you'll have to jump through these hoops.
You may also get a response if you email apac(at)wizards.com - outside North America it may be that you can get a DCI number from them.
Hope that helps - there's plenty of advice available in the
RPGA forums, and the
LFR group on the WotC site.