Bob,
sorry I wasn't very clear. i understand how to do it if it is tagged in the camera. what would be cool is if the selects (tagged) in photomechanic on the computer could be linked back to the card to download just those raw files.
OK, now I understand what you're getting at. Once you have tagged the already downloaded JPEGs, you want to download their RAW counterparts and not download any of the other images at all.
We'll think on that one for a while. Ingest doesn't know anything about the contact sheet you're currently browsing. It does know about images that it had previously downloaded but things could get complicated if you have renamed the images or modified them significantly.
-Kirk