I'm sure it is a case of "must" rather than "may want to" or at least it's the most sensible way. This is easy enough to do on a Commodore 64 and it can't be harder on an Arduino. All you need is the shape of the array and the location of the cell in question.
If you're referring to this statement then I think I was agreeing with you when I said this:
the Excel file in question could be converted to CSV prior to the using the arduino to extract the information. At least it doesn't sound as far fetched as the OP's question (that being extract the data from an Excel (non-CSV file).