I\'d like to know if it is possible to query a past exchange rate on Google Spreadsheet.
For example; using formula =GoogleFinance(\"CURRENCY:USDEUR\")
The instructions for all related to googlefinance are in here: https://support.google.com/docs/answer/3093281
Remember the actual Google Spreadsheets Formulas use semicolon (;) instead of comma (,). Once made the replacement on some examples would look like this:
For a 30 day INDEX of USD vs EUR you should use (note that in the case of currencies they go together in the same first variable):
=INDEX(GoogleFinance(USDEUR;"price";today()-30;today());2;2)
TIP: You can get the graph over the entire size of the cell by simply changing INDEX for SPARKLINE, like this:
=SPARKLINE(GoogleFinance(USDEUR;"price";today()-30;today());2;2)