One way:

Put a dummy/blank worksheet after Sheet1 and another one before SheetN,
perhaps named "Start" and "End". Use the formula

=SUM('Start:End'!O4)

put as many sheets in the middle as you like. You can hide the dummy
sheets if you like.


In article ,
pfrieder wrote:

I have a workbook with n worksheets. I would like to sum the cells from
Sheet2 to Sheet(n-1). The names of sheets 1 and n are static, but names on
other sheets change. Is there any way to do a 3D reference with an offset in
the worksheet specifier, so that the formula works regardless of the number
or names of the worksheets in the middle? Something like
=SUM(('Sheet1'+1):('SheetN'-1)!O4)