Generally you would normally open the file in WORKS and then save it down as a
file that Excel can read.  .xlr is a native Excel format, or .txt, .csv, dbaseIV
are all formats it can read.   You can also find a converter here if you don't
have WORKS.

http://www.rl-software.com/indexjs.htm?/converter/wkscnvxls_e.htm

Text from the website above:-

Microsoft does not provide an import Excel filter for Works-WKS files later than
version 2. (for Works-WPD and Word they do). There is no standard way to convert
a lot of Works-WKS files into the Excel format. You need to save each file out
of Works manually into XLS which is a pain in the neck. Here comes our MS Works
Spreadsheets to Excel Converter. It does not need a Works Installation and you
can use the batch converting wizard (see right side).
 a.. Completely integrated into Excel 97/2000/XP, no external program
 b.. Imports MS Works Spreadsheet (*.WKS) 3.x ,4.x, 200x files
 c.. Convenient, selfextracting and selfinstalling setup procedure
 d.. Can be removed completely with standard deinstall procedure
 e.. Works with Windows 9x, ME, NT 4, 2000, XP
 f.. Our RL-File-Conversion-Wizard is part of the package
 g.. Converts cell alignments, font styles, etc.
 h.. Excel helper macros to make migration easier
 i.. No need for a Works installation
 j.. Free Updates: Our registered customers can download the latest version
from our download area at any time

Two articles from Microsoft that deal with Works and the files it can open/save
as.

Works: Sharing Works Files with Other Programs
  http://support.microsoft.com/default.aspx?scid=KB;en-ca;271080

Works: Limitations of Sharing Files with Excel
  http://support.microsoft.com/default.aspx?scid=KB;en-ca;269273