I am not being a great help, but if you have broadband (or are very patient) or better, the Open Office suite might be the solution to take care of these .xls files. Open Office is completely free, and is able to open most standard files without problem (Excel files work well enough there).
If you are interested, the site is available
here. Be warned that the current Version weights a bit more than 60 mo (at least, the Last English Version for Windows), and so patience will be required if you have low download speeds.