Yes, it appears to be. The easiest way to find out the answer to this question is to read the docs on cpan. Example code follows:

#!/usr/local/bin/perl

use warnings;
use strict;

use Spreadsheet::WriteExcel;

my $workbook = new Spreadsheet::WriteExcel("new.xls");
my $worksheet = $workbook->addworksheet();
$worksheet->set_landscape();
[download]

--RT