Thank you very much for your quick reply.
I tried what you suggested, and even did some modifications, however it does not work as expected. Just shows the 'name' and 'email', or only 'email'.
Hoever I found a common sense workaround:
I remapped my shared ldap address book like this:
# 'name' => 'cn',
'firstname' => 'givenName',
'middlename' => 'sn',
'surname' => 'locality',
and that works
The important thing is to hide the 'name', so that RC tries to construct it from firstname+middlename+surname.