I have two excel spreadsheets with identical formats. I would like to generate a third spreadsheet with the same format, with the contents of each cell of the third spreadsheet being the sum of the contents the corresponding cells on the first two spreadsheets. I want to add the numbers, but not the row and column headings, which are identical on the two spreadsheets. I would like to do this with a simple command, without entering formulas in each cell on the third spreadsheet. How can I do this?