Maybe you could use the User Defined Function PrevSheet for the "carrying
over".
Function PrevSheet(rg As Range)
n = Application.Caller.Parent.Index
If n = 1 Then
PrevSheet = CVErr(xlErrRef)
ElseIf TypeName(Sheets(n - 1)) = "Chart" Then
PrevSheet = CVErr(xlErrNA)
Else
PrevSheet = Sheets(n - 1).Range(rg.Address).Value
End If
End Function
Say you have 65 sheets, sheet1 through sheet65...........sheet names don't
matter.
In sheet1 you have a formula in A10 =SUM(A1:A9)
Select second sheet and SHIFT + Click last sheet
In active sheet A10 enter =SUM(PrevSheet(A10),A1:A9)
Ungroup the sheets.
Each A10 will have the sum of the previous sheet's A10 plus the sum of the
current sheet's A1:A9
To enter new products on each sheet you can also group the sheets and add a new
product on the activesheet, which will be replicated on each sheet.
Gord