Help creating a currency exchange formula

Need help creating a formula that will let me enter us dollars, Haitian Goudes, or Haitian dollars and the other columns. Need to be able to enter the values in any of the three categories, and have it convert and fill in the other categories. I work in orphanages in Haiti and this is to track purchasing. The values do not need to interact with the internet, as I will be cashing at different exchange rates and will manually adjust for the rate I received

Date Items Us Dollar Goudes Haitian Dollar Receipt

Dollar 1
Goudes 45
Haitian dolar 8

Thanks so much for any help. Scottc@visiontrust.org

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Purchasing spread sheet.xlsx28.52 KB