Excel 2007 : Automating Header/Footer Formatting

I produce a report every month which consists of about 15 separate Excel workbooks, each containing between 6-10 worksheets each.

The formatting of these workbooks as far as page orientation changes from worksheet to worksheet. Some are portrait 8.5 x 11 some are 11x17 landscape. There is a special header and footer that, for a reason I cannot explain, MUST be entered after all of the worksheets have been populated with datat and formatted. Adding the special header and footer information on every worksheet MUST be done as the very last step.

Unfortunately, if you "Select All Sheets" and add the headers and footers at the very end ... all of the page orientations of all the workbook worksheets change and all the worksheet formatting is lost. Grouping or selecting all the worksheets in order to add the special header footer to ALL the worksheets in the workbooks seems to make Excel choose to change the workbook formatting to be the same for ALL worksheets -- yes, the special header/footer is added...but the formatting of the entire workbook is now screwed up.

Is there any way to automate adding header/footer data for multiple worksheets without affecting the formatting of all of them in a wookbook?

Thanks

(Been doing this for 18 months. Just though "hey...maybe an Excel users group might have the answer.)