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).
Colouring sounds like a good solution in this case. Additionally, if you wanted to, you could use the control's MouseOver event handler to update a label on your form with some information as the user moves the mouse over the relevant ranges.
You're advice about using Excel event handlers got me thinking.
Using Workbook_Open() to automatically fire-off some code when a user opens the spreadsheet that is output from the database/OWC11 spreadsheet, that searchs through the used range looking for "red text" (that indicates tagged/manipulated data - or different types of formatting which can be used to indicate different options selected during the creation of the spreadsheet by the database) and then converting this to comments, is a bit of cludge but gives the desired result.