You can use the Minor Planet Ephemeris Service to generate co-ordinates for your location.
http://minorplanetcenter.net/iau/MPEph/MPEph.html
A number of planetarium programs will allow you to display the positions of asteroids.
Best chance for a visual observation from Australia is on the night of April 20-21 (although from northern locations the morning of April 20 might be OK too)
Peter Thomas
Oakleigh