Setting LDAP_SERVER_PERMISSIVE_MODIFY_OID to allow empty values in AD

Hello,

I have a script which reads phone numbers from a CSV file
and stores them in Active Directory (w2k3), so that you can
find a user phone number in the address book of Exchange.

I get error messages:
"comment: Error in attribute conversion operation, data 0, vece"
which I can get rid of only if I set every new empty value
to some string, for example to "n/a".

After some searching I've found a suggestion to set
LDAP_SERVER_PERMISSIVE_MODIFY_OID so that
AD does not prevent me from emptying empty values:
http://msdn.microsoft.com/en-us/library/aa366984.aspx

Does anybody please know how to set it in Net::LDAP?
And what value should I use, "1.2.840.113556.1.4.1413"?

Thank you
Alex

PS: Here is my entire script:

#!/usr/bin/perl -wT

use strict;
use Net::LDAPS;
use Data::Dumper;

$ENV{PATH} = '/bin:/usr/bin';
$Data::Dumper::Useqq = 1;

use constant ROOTDN   => 'OU=User Accounts,DC=XXXX,DC=com';
use constant DOMAIN   => 'XXXX.com';
use constant SERVER   => ['ablwdc01.' . DOMAIN, 'ablwdc02.' . DOMAIN,
'ablwdc03.' . DOMAIN];
use constant ADMIN    => 'Admin';
use constant ADMPW    => 'XXXXXX';

my ($ldap, $search, $mod, $href, %phones);

$ldap = Net::LDAPS->new(SERVER) or
        die('Can not connect to LDAP server');
$ldap->bind(ADMIN . '@' . DOMAIN, password => ADMPW) or
        die('Can not bind to LDAP server as ' . ADMIN);

while(<>) {
        tr/"//d;
        tr/\r//d;
        next unless /^([^,]+),[^,]+,([^,]*),([^,]*),([^,\n]*)/;
        my ($full, $home, $mobile, $fax) = ($1, $2, $3, $4);

        $full =~ s/\xDF/ss/g;
        # replace german umlauts by asterisks
        $full =~ s/[\xC0-\xFF]/\*/g;
        # split full name in first and last name
        next unless $full =~ /^(\S+)\s+(\S+)$/;
        my ($last, $first) = ($1, $2);

        my $filter = "(&(objectCategory=Person)(objectClass=User)
(givenName=$first)(sn=$last))";

        # WORKAROUND: AD does not like it if you set
        # empty attributes to empty, so use 'n/a' as default
        $phones{$filter} = {HOME => $home || 'n/a', MOBILE => $mobile
|| 'n/a', FAX => $fax || 'n/a'};
}

#print Dumper(\%phones);

while (my ($filter, $href) = each %phones) {

        $search = $ldap->search(
            base    => ROOTDN,
            attrs   => [qw(givenName sn)],
            filter  => $filter,
            sizelimit => 1,
        );

        $search->code() && die $search->error();

        foreach my $entry ($search->entries()) {
                my $givenName   = $entry->get_value('givenName');
                my $sn          = $entry->get_value('sn');

                next unless $givenName && $sn;

                printf STDERR "%-16s %-16s -> %16s %16s %16s\n",
                    $givenName, $sn, $href->{HOME}, $href->{MOBILE},
$href->{FAX};

                $mod = $ldap->modify($entry, replace => { homePhone =>
$href->{HOME},
                     mobile => $href->{MOBILE},
facsimileTelephoneNumber => $href->{FAX} });
                $mod->code() && die 'Failed to modify user: ' . $mod-
>error();

                #$entry->dump;
        }
}

$ldap->unbind();