Foreign currency total, balance sheet accounts

Simple problem, but can’t find a solution. I have a B/S account (prepaid exp) which is not a cash account and which is denominated in a foreign currency. I cannot find a way to determine its balance in its own (foreign) currency. So the question; How much have we actually paid to date, in the vendors currency, is a non-trivial question. Do we have to keep a separate (read - back-of an-envelope) record? Thanks.

You can’t denominate balance sheet accounts in foreign currencies unless they subsidiary ledgers (bank accounts, petty cash, credit cards, etc.) of the Cash Accounts tab. So what exactly are you referring to? How did you create this account? Can you post a screen shot of its edit screen?