When I export my expense report from the left hand corner of the dashboard to excel, it does not report the different currencies of my transactions.
When exporting the report to Excel, the company's currency is used instead. That's why you're using no currency symbol.
You can pull up the Transaction List by Vendor report instead. Then, customize it to show the Foreign Amount (currencies).
It would depend on you if you wanted to save this customization. This will help you access the report easier in the Custom report tab.
We'll surely keep on posting answers if you have any other questions.