Bad filter in Active Directory: (!company=mycompany)

Hello,

I've written a short script to prepend "ext-" to mail addresses
of all external colleagues in Microsoft Active Directory:

    filter  => '(&(objectCategory=Person)(objectClass=User))',
....
    $mail = "ext-$mail"
        if $entry->get_value('company') !~ /mycompany/i
            && $mail !~ /^ext-/;

For better performance I'd like to move
the company test to the search filter:

    filter  =>
'(&(objectCategory=Person)(objectClass=User)(!company=mycompany))',

Unfortunately it fails with: Bad filter at ....

If I remove "!" it works ok. If I try that filter with dsquery:

dsquery * domainroot -filter "(&(objectCategory=Person)
(objectClass=User)(!company=mycompany))

- then it works too. Has anybody seen the same problem?

Thank you
Alex


PS: Here is my entire script:

#!/usr/bin/perl -wT

use strict;
use Net::LDAPS;

$ENV{PATH} = '/bin:/usr/bin';

use constant ROOTDN   => 'OU=Imported,OU=User
Accounts,DC=mycompany,DC=com';
use constant DOMAIN   => 'mycompany.com';
use constant SERVER   => ['wdc01.' . DOMAIN, 'wdc02.' . DOMAIN];
use constant ADMIN    => 'Admin';
use constant ADMPW    => 'XXXXX';

my ($rot13, $ldap, $search, $mod, $href);

($rot13 = ADMPW) =~ y/A-Za-z/N-ZA-Mn-za-m/;
$ldap = Net::LDAPS->new(SERVER) or
        die('Can not connect to LDAP server');
$ldap->bind(ADMIN . '@' . DOMAIN, password => $rot13) or
        die('Can not bind to LDAP server as ' . ADMIN);

$search = $ldap->search(
    base    => ROOTDN,
    attrs   => [qw(company mail givenName sn)],
    filter  => '(&(objectCategory=Person)(objectClass=User)(!
company=mycompany))',
);
$search->code() && die $search->error();

foreach my $entry ($search->entries()) {
        my $mail = lc $entry->get_value('mail');

        # prepend "ext-" if not "mycompany" and "ext-" isn't there yet
        $mail = "ext-$mail"
             if $entry->get_value('company') !~ /mycompany/i
                  && $mail !~ /^ext-/;

        $mod = $ldap->modify($entry, replace => { mail => $mail });
        $mod->code() && die 'Failed to modify user: ' . $mod->error();

        printf "%-15s %-15s %-15s %s\n",
            $entry->get_value('company'),
            $entry->get_value('givenName'),
            $entry->get_value('sn'),
            $mail;
}

$ldap->unbind();