We are sending the amount of our orders in order's currency and the Analytics account has default currency as USD. It seems our platform does not do the conversion before is sent, therefore the exchange is done by Adobe. Which is the exchange rate used by Adobe? I do not manage to spot this in the documentation.
this featue is not available to my knowledge in Analytics at this time. (Please correct me if I am mistaken)
How ever Data Workbench can do what you are wanting to do. If you set the currency code at the page level then it is recorded in that row of Data. The conversion to usd happens post processing. In Data Workbench we could read in the pre and post fields to give you both values and allow for you to report both ways.