Adding keywords to FITS headers

Hello all,

I'm relatively new to AAVSO and have started submitting my data.  I do my preprocessing with AstroImageJ which fills in everything in the FITS header except FILTER and CALSTAT.  Filter is no problem because I've been prompted to fill it in, and Vphot updates all the files.  CALSTAT is another issue as there is no way to update all the uploaded files with BDF even though the files have been calibrated.  As a result all my uploads have a red calibration box.  One way I can get around it is to stack the files and download the stacked image, update in AIJ, and then upload the stacked image and do my photometry report with that file.  I could also go into AIJ and add CALSTAT to each file I'm uploading, but lots of work for timed collects.f

Thus the question is, is there a way to do batch updates to FITS headers?  I would need to add CALSTAT as a keyword and BDF as the value.

Thanks for any help.

Clear skies,

Steve