What to do when not enough points for return flight?

Hi, I have enough Qantas FF points to fly one way to Europe but have to purchase a return flight. When I look at doing that I am charged in Euros. Is there a way to book and be charged in A$? I thought I had seen something written about this but can’t find it. Thanks

Just off the top of my head.

Try redeeming Europe-Aus with points and buying Aus-Europe with cash/ccard?

The currency is usually based on the departure city.

If that doesn’t work, please let us know.