You could create a template workbook (*.xlt) and format all the cells with the
numberformat you want.
Then use that whenever you want to use that special format.
If you want to use that number format for all new workbooks, name the template
workbook book.xlt and store it in your XLStart folder.
If you save another copy as sheet.xlt, then any new sheet added to an existing
workbook will inherit that number format.
