Update: Looks like I missed the code far down in the IFRAME. I'm not sure if I'm converting from the format you have, but the following should help you.

use strict;
use warnings;

use Win32::OLE ();

# Constants for the NameTranslate object.
use constant ADS_NAME_INITTYPE_GC => 3;
use constant ADS_NAME_TYPE_1779   => 1;
use constant ADS_NAME_TYPE_NT4    => 3;

# Specify the Display Name of the user.
my $nt_name = $ENV{USERDOMAIN} . '\\' . $ENV{USER};

# Use the NameTranslate object to convert the Display Name
# of the user to the Distinguished Name.
my $name_translate = Win32::OLE->new('NameTranslate')
   or die("Unable to load NameTranslate OLE object\n");

# Initialize NameTranslate by locating the Global Catalog.
$name_translate->Init(ADS_NAME_INITTYPE_GC, "");

# Use the Set method to specify the NT of the object name.
$name_translate->Set(ADS_NAME_TYPE_NT4, $nt_name);

# Use the Get method to retrieve the Distinguished Name of the user.
my $user_dn = $name_translate->Get(ADS_NAME_TYPE_1779);

print("$nt_name => $user_dn\n");
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For me, the output is

MYDOMAIN\myuser => CN=MyLast\, MyFirst,CN=Users,DC=mycompany,DC=biz
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