It was suggested by QB employees to use the balance sheet detail report and show the exchange rate column to manually calculate this. As previously stated this will not work because you don't know the beginning balance rate.

The only way that I have found to find the ending foreign balance is to run a General Ledger report and have the 'Foreign Amount' column showing. In addition you have to select to generate the report for 'All Dates.' If you run it for 'All Dates' then you can see the first line should be 'Opening Balance.' It will show the home currency equivalency in the 'Amount' and 'Balance' columns and it will show the foreign currency amount in the 'Foreign Amount' column. If you export the file as an excel file then you can select this first foreign amount and drag down to the date you need to see the balance for that account and in the excel footer window you can see the sum to that date. 

As far as I know this is the only way to see a foreign balance at a specific point in time. Unfortunately it has to be done manually and unfortunately you have to export all the data for all dates to get the opening balance to work from but at least there seems to be some way to get the data out of QBO.