Microsoft Excel 97–2003
I understand you're looking for a download link for (likely the .xls version). However, I must clarify a few important points before providing guidance:
.xls files
If you need to work with (Excel 97–2003 format) without paying for modern Excel, here are legitimate options:
Microsoft Excel 97, 2000, XP (2002), and 2003 are proprietary, copyrighted software products.
They are not legally available as "freeware" from legitimate sources, except in very specific cases like: