Save file, ask to add keywords?

[cycletheory]

I'm not a coder, so finding a solution is a problem. I don't even know if Hazel or AppleScript or Automator is the right solution.

When I "Save as..." a file, wherever, I would like for "it" to add one or multiple keywords to the file. Not just Spotlight Comments, but keywords written to the EXIF data; the same keywords written if you use a program, such as Picasa or iPhoto, etc.
It would be awesome if I could modify the OS's "Save As..." dialog box to include a field to include keywords separated by commas or something. ...but I am guessing this is a bit too complicated.

ANY help would be really appreciated. I've been trying to come up with a solution for months and months.

[Mr_Noodle]

If you want to write that info to the EXIF data then yes, a script at some point would probably be required. There might be a commandline program out there you can leverage but you'll still have to use a script to trigger it properly from Hazel.