#!perl
use warnings;
use strict;
use Win32::OLE qw(in); # import "in"

my $excel = Win32::OLE->new('Excel.Application', 'Quit');  
$excel->{Visible} = 1;
# q:\s\test.xls is a new worksheet with three sheets
my $xls = $excel->Workbooks->Open('q:\s\test.xls'); 

foreach my $sheet ( in $xls->Worksheets ) {
    print $sheet->Name, $/;
}
__END__
Output:
Sheet1
Sheet2
Sheet3