Kontact: How to expand a ldap search to non-standard ldap fields?

Hallo,

well, I hope I have chosen the right mailing list for my questions; if 
not so please let me know (and suggest a better one, perhaps).

My problem is as such: I have set up a Kolab server (very nice, by the 
way), and use Kontact as user program (very nica also).

Now we have some fields we would like to use in a simple adress/kontacts 
search. For example I have (mis-)used the attribute type carLicense of 
inetOrgPerson to stuff some data into.

So, is there a possible way to get this field involved, when a search 
for a person is made, just in the same way when, say, a surname (sn) or 
part of a givenName is entered?

I would be glad for some hints.

Best regards,
Christian