There is an international dial plan available for Australia, however there are two considerations you need to be aware of:
Firstly, this AUNP is only available for registered users, secondly, and more importantly you can only install and integrate dial plans with Cisco CallManager version 3.3(4) and later.
Take a look at the following URL:
http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/idp/deploy3.htm