Example XML:

<one>
	<two>
		<three>
		value
		</three>
	</two>
<one>


##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;


my $DATA;
my @keys=qq(one two three);# Data we captured from parsing above XML
my $newhash=&pfm(@keys,'value');# Make a new hash?
$DATA={%$DATA,%$newhash};# Slap it back into the main data hash, repeat as necessary?

sub pfm{

}

print Dumper $hash;

$hash = {
          'one' => {
                     'two' => {
                                'three' => 'value'
                              }
                   }
        };