Ability to have unit prices convert automatically to the selected currency when creating a PO.

Let's say my account's base currency is in USD but I have additional currencies on my account. For Example ILS and ZAR. When I upload my product list to the system I have "Item A" which is uploaded for $7 USD. When I create a PO and select the currency to be ZAR and then select "Item A" to be purchased, the unit price of the Item should automatically convert to R 102,57 ZAR. If I then decide to select the currency to be in ILS the unit price should then automatically convert to ₪ 22,92 ILS. The opposite should also be true that If I were to add a new item and the currency I selected is different form the base currency, then the unit price should be converted to the base currency when selected, as well.