copy tags from JPG to DNG?

[deb27]

I have folders full of photos in which I have both a RAW image and a corresponding JPG image. For example:
photo1.dng
photo1.jpg
photo2.dng
photo2.jpg
etc.

I am currently moving my photo process from using Picasa to Lightroom. Lightroom understands that the jpg is associated with the dng. But my problem is that I have some metadata in the jpgs (such as Caption-Abstract, Description, ImageDescription and Keywords) which are in the jpg but not in the DNG.
I would like to copy this metadata to the DNG file.

I have been reading about -TagsFromFile and this appears to be the right option but I'm baffled as to what the syntax should be.

I'm pretty sure that I just want to copy each of the tags mentioned above from each JPG file to the DNG file which has the same filename (prior to the extension) and leave everything else unchanged.  There are no xmp sidecar files to worry about.

Thanks

[StarGeek]

There's a similar example in the copying examples, except it's copying from CR2 to jpgs.  Also, this post from the forums.

Your command should be something like this, but test it out first to make sure:
exiftool -tagsfromfile %d%f.jpg -Caption-Abstract -Description -ImageDescription -Keywords -ext DNG  dir

You might also want to copy -Subject, as Picasa writes keywords to that tag as well.  I don't think Picasa writes to ImageDescription, though.