LDAP search for contacts in Exchange 2003 Public Folders

I need to run an LDAP search for contacts in Exchange 2003 public folders. It's need for a desktop software UC Express for a Mitel 5000 phone system.

The best query example I found is:
 (&(&(proxyaddresses=*)(|(objectclass=user)(objectclass=publicFolder)(objectclass=group)(objectclass=Contact))))

http://forums.msexchange.org/m_1800446120/mpage_1/key_/tm.htm#1800446120

but the results give all the Public Folder objects not the content of the folder.

The typical location is:

-Public Folder
--Company Folder 1
---Company Folder 1a
---Company Folder 1b
---Company Folder 1c
--Company Folder 2
---Company Folder 2a
---Company Folder 2b
---Company Folder 2c
--Company Contacts*

* this is the folder I need to query.

Help