print "Content-type: application/vnd.ms-excel\n";
print "Content-Disposition: attachment; filename=yourfile.xls\n";
print "\n";

##</code><code>##

#!/usr/bin/perl -w
use strict;
use CGI;

my $query = new CGI;
print $query->header(
  -type => 'application/vnd.ms-excel',
  -content_disposition => 'attachment; filename=yourfile.xls'
);

binmode STDOUT;