Exclude Local Folders From Global Searches?

Oh boy... thought I had this solved but I didn't.

I do global searches across multiple mail accounts and move the results to local folders to archive them.

The problem is that when there are already archived messages in the local folders, then the global search shows not only the unarchived messages in the live mail folders, but the already archived messages in the local folders. I only want to show the unarchived messages in the mail accounts and exclude the local folders that contain already archived mail.

I have not been able to find any way to exclude the local folders from the global search. I tried using not in:[local folder name] in the query but that didn't work (although I am not sure why not ... maybe the excluded folder has to be in the current mailbox?).

Is there any way to make this work that isn't mean and ugly? Thanks for any help!