cant you simply buy gold in AUD then short sell off the USD.
If you do this, you have bought gold, with AUD as per any normal transaction.
Then you place a short sell the USD. In this regard you are 'selling USD' to buy AUD.
In this regard you have USD transferred into AUD, you then have AUD transferred into Gold.
The end result is having Gold that that is reliant on the price of USD.
Dunno if this is exactly what you are talking about, but in this regard you could actually buy physical gold, place it under your bed yet still have it moving in price vs the USD.
