gistfile1.pl

use strict;
use utf8;
use XML::LibXML;
use Encode;

my $xml = encode('euc-jp', <<EOXML);
<?xml version="1.0" encoding="euc-jp"?>
<foo>
    <bar attr="日本語">日本語のbar</bar>
</foo>
EOXML

print "XML -> $xml\n";

my $dom = XML::LibXML->new->parse_string($xml);
my $xpath = encode('euc-jp', '/foo/bar[@attr="日本語"]/text()');
print "XPath -> $xpath\n";
my @nodes = $dom->findnodes($xpath);

use Data::Dumper;
print Dumper(@nodes);