how do i get a top 20 shareholder list?, page-3

The share register is legally to be made available to all shareholders in a company if they go into the registered office of the company and ask to view it.
(appointment of course)
Many will email it out to you if you're not in the same city, and they are entitled to charge you a fee if they have to email it to cover their administrative costs.
See Corporations Act: (I didn't look up the section for you, but you can find it if you browse headings)
http://www.austlii.edu.au/au/legis/cth/consol_act/ca2001172/