Not quite sure what you're doing, but maybe you could use a macro:

Option Explicit
Sub testme01()

Dim iCtr As Long

For iCtr = 1 To Worksheets.Count
With Worksheets(iCtr).PageSetup
.LeftHeader = "Number: " & Format(iCtr, "000")
End With
Next iCtr
End Sub

I'd record one when I did the page setup manually for one page and then try to
generalize it and cycle through the worksheets.

If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm

itguyintrainin wrote:

I am trying to automatically number 35 sheets within the same workbook, using
the header/footer custom option. I am unable to get each tab to see one
another and sucessfully number each tab (sheet) within the workbook. It will
start to number a few, then the formatting will stop. I am running Office XP
SP3, on XP SP2. All help greatly appreciated.

--

Dave Peterson