only want to convert shipping price?

Creating an online store using woocommerce, We are located in Australia, but like to use our paypal account in US$ for our own reasons.
Our business is mainly selling parts overseas (90% to the US) and have always found it easier to deal world wide in $US, and would prefer to keep it that way.as would also like the payments going into paypal in US$

I have created items and it has them listed in US$, but tried the AusPost plugin and it adds the shipping price in US$ but not converted..
ie; cost is AU$7.60 to post, and it adds it to invoice but US$7.60 Is there a away around this?
Here’s an example of my issue…
Item = US$10.00 and Australia post plugin works shipping to be AU$7.65 But the checkout shows it all in $US
EG;
Item $10.00
Post $7.65
TOTAL $17.65
I need the $7.65 (post) to be converted to $US
going off google exchange rate it should show;
Item $10.00
Post $5.86
TOTAL $15.86

Is this something currency converter lug in can do? or is something I need to sort with AusPost plugin??
Thanks, Brett.
https://mikesclassiccyclespares.com