An update from me.

>>... It's a relatively easy
>>process to write a set of routines that list all of the styles in a
>>workbook, list all of the ACTIVE styles, and delete those that are
>>unused.  The routines use a brute force method of checking individual
>>cells, which sounds slow, but really isn't.  I will send you an Excel
>>file with these routines separately (do something nice for me someday).
>>
>>Stan Scott
>>New York City
>
>...
>However, I'm not clear how these relate to custom number formats.  A
>style contains all formatting information, font, borders, etc as well as
>number format.  If "custom" number formats are saved as styles, how are
>they named?  A quick search in help found a "DeleteNumberFormat" method
>but no methods or properties to list them.

A more extensive search in help and the object browser show that you can
find number formats in use with the .NumberFormat property of
cells/ranges, and the above mentioned DeleteNumberFormat method.  By
looking at the Excel file as text I could see the extra, unwanted number
formats as text strings, and then manually write some code to delete
them, but there does not appear to be any way to retrieve them using VB.
 Thanks Microsoft!

regards, Joe