Sage 50 Canada

I have an issue with a previously filed tax year where the US exchange rate was posted extremely wrong ($537.61USD = $3016.97CAD). Since it was not corrected when the filing was done, how do I now correct it? I am assuming I need to make an adjustment…

Our business has a new US Visa Card to pay for expenses in USD. I want to set up a new visa card but Sage 50 does not allow me to choose the currency for the credit card? Anyone knows how to do this? I'm using Sage 50 Premium Accounting. Many thanks…