Sync specific files based on tags

I have a folder containing many items. I sometimes flag certain items that I want to review, using the tag "Flagged." Technically a Spotlight comment, since I am not yet on Mavericks.

I would like to maintain a second folder in Dropbox that has only the tagged "Flagged" files. A smart folder won't work, because the contents don't get uploaded to Dropbox. I thought I could do this with Hazel, but I can't figure out how to remove documents from the Flagged folder once I remove the "Flagged" tag in the master folder. Can this be done?

I don't think you can do that without using a script. It's a bit of an odd case.