#!c:/perl/bin/perl

use strict;
use Win32::API;

my $filename = "C:\\Invoices\\foobar.pdf";

my $shellopen = new Win32::API("shell32", "ShellExecute", 
                             ['N', 'P', 'P', 'P', 'P', 'I'],
                              'N');

$filename =~ tr!\\!/!s;

$shellopen->Call(0, "print", $filename, 0, 0, 0);