Demo? I've had this code lying around for ages:

#!/usr/bin/perl -wl

use strict;

my $target = 'IHBT';

print "target contains       : $target";

my $target_address = \$target + 0; # nummify
my $native_version    = pack 'L', $target_address;
my $pointer = pack 'P', $native_version;

print "target address        : ", sprintf('%x', $target_address);

my $sv = unpack('P4', $native_version);
print "deref'd packed (sv)   : ", sprintf('%x', unpack('L', $sv));

my $pv = unpack('P4', $sv);
print "deref'd sv (pv)       : ", sprintf('%x', unpack('L', $pv));

my $value = unpack('P' . length($target), $pv);
print "deref'd pv (value)    : ``$value''\n";
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I hope it helps. :)