Mmmm ......
"Whirls" has it right ...... things have really changed in the world of rotary aviation since I started ....
Used to be you could get yourself an FAA CPLH and go around the world on it ... not now.
As an Aussie you SHOULD get yourself a Oz CASA CPL (and preferably get the ATPL and IFR credits as well) this will give you a credible license to learn "the **** you'll need to learn". Then the really hard part ...getting that first job.
Probably ... nobody anywhere will want to employ you (as a 'slave' maybe???) with less than 1000hrs P1 so that will take you some time to achieve ....
And then there is the fact that employment in foreign countries is much more restrictive than it used to be .... to work in Europe you need the 'Pink Passport' and very often the appropriate language to go with it (?). Other countries around the world now have their own 'Nationals' who have since the early 80's gotten their own qualifications and experience and will (quite naturally) have priority of employment .... and this will not get any easier with time.
The 'BIG' companies who will employ you to work contracts 'overseas' will require very specific skills and qualifications and usually lots of logged air time .... they usually want 'Captains' to command the aircraft to keep the locally hired 'co-jo' in order (and the a/c in one piece) .... that is the way it is ..... Yes there MAY be exceptions to what I have said above ...but you will have to be lucky to find those.
Good Luck with your efforts .....
Cheers