I put all my desktop items and documents etc on a flash drive and put that into the new computer. Most everything is fine, except that. It was a desktop item. I didn't know of any other way to move the spreadsheet?
Boot up the old XP computer, right click the shortcut that points to the spreadsheet and choose properties.
Look at the Target value it should show you the actual location for the real file. Browse to it and copy the file(s) and or folder(s) as needed to your flash drive and transfer the actual file rather than the desktop shortcut to a suitable location on your new Windows 7 computer.
As far as a program to handle the reading or creating of spreadsheet style documents there are several, I would suggest using the same...