@NameLookup() - how to exclude local Directories from lookup?

Hi guys

Do you know how to exclude local address books from looking up through when you use @NameLookup()? It would be nice if someone shares such tip.

I bet some of you (if you are Lotus Notes developers) worked on task where you have to analyze a bunch of addresses from 'SendTo/CC/BCC' which could be Internet addresses (either external or internal), Notes canonical names, Notes short names, Notes-names with Domain part or without Domain part to do finally one job on internal users and another job on external users.

Something like, SendTo=John Doe/Org; jd, jd@google.com, jd@nativedomain.com, CN=John Doe/O=Org, John Doe/Org@Domain, jd@yahoo.com ....

The easiest way could be using of @NameLookup() to get f.x. FullName item from Person-document in server Domino Directory: if you get something, then it is an internal user, if you get nothing, then, it is rather external user. However I want to exclude any lookup through local names.nsf(s) and I can't get how to do that. I tried all options which I thought could work but each time local names.nsf were taking into account.

Note*: my environment has more that one Domino Directory so @DbLookup() through "($Users)" view of server names.nsf will not help here.

Of course, I know how to do it using lotuscript but it would be really nice to use @NameLookup() instead.