use warnings;
use strict;
use XML::Twig;

my $myXML = <<EOF;
<?xml version="1.0"?>
 <reports xmlns:xi="http://www.w3.org/2001/XInclude">
 <xi:include href="xinclude.xml" parse='xml' />
 </reports>
EOF
my $t = XML::Twig->new(twig_handlers => {'xi:include' => sub { print $_->att('href') } });
$t->parse($myXML);

__END__

xinclude.xml