Thanks Colin,
I'm using the spreadsheet to produce output from the database in the form of Excel files (and manipulation/display of the output data will be done within Excel). Since the user has a number of options for flagging/handling various scenarios with the data prior to output (eg replace "missing" entries for a date range with either zero, leave as null, or insert "NA" etc) it would be "nice" to tag such manipulated data in the output spreadsheet with a comment. If comments for cells cannot be produced by OWC11, I was thinking of just using cell formatting instead (eg red text indicates tagged/manipulated data).
Thanks again.