> searching dejanews for `xls' and `dll' would probably lead you to
> `shtdll14.zip'; search for that.  I don't know what version of XLS
> files it would read.

I did some more searching last night, and found these, too:

    http://www.wotsit.demon.co.uk/database/biff.zip
      includes code to write (not read) Excel files

    http://www.wotsit.demon.co.uk/database/msoffice.zip
      how to get MS Office file format information for free

    http://www.scitek.demon.co.uk/html/body_excel_toolkit.html
    http://www.scitek.demon.co.uk/html/body_download_page.html
      libraries for MS Windows and Unix (!) to read Excel files

    http://www.istonline.com/
      search for Data Conversion
        search for OpenExchange (and OpenExchange DLL)