QB reports will present amounts in home currency also you have the option to view Realized Gains/Loss and Unrealized Gains/Loss Reports. for each transactions you can enter prevailing exchange rates manually on the relevant screens e.g. Deposits,Receive payment,Invoice etc. Also you have the option to update exchange rates through QB move to Company > Manage currency > download latest exchange rates.
To calculate foreign amounts in the latest exchange rates use Home Currency Adjustment. Company > Manage currency > Home Currency Adjustment and enter the latest exchange rates QB will update any exchange rate Gain/Loss based on the rates you entered and the account balances.
Note: Discuss with your tax consultant regarding the Unrealized Gains/Loss for tax purposes.
Comment back for further clarifications / to discuss.