[M_Six]

Do you also have Adobe Bridge available? If so, open the folder in Bridge and pick the first of the files you want to fix and open it in RAW. Make your WB changes and then hit Done. Once you're back in Bridge, pick a bunch of the files to be fixed (not too many at once or it might lock up your machine) and go to Edit => Develop Settings => Previous Conversion. It should take the settings you used for the first image and apply it to the rest. This is how it works in CS5. I don't have CS4 so I have no way to see if it works the same.