JPB,

Enter the code below in to a codemodule, and use it like:

=SpSum(A1:A150,B1:B150,"V",30)

HTH,
Bernie
MS Excel MVP

Function SpSum(R1 As Range, _
R2 As Range, _
Ignore As String, _
Pop As Integer) As Double

Dim myRow As Long
Dim myCount As Integer

myCount = 0
SpSum = 0

For myRow = R2(R2.Cells.Count).Row To 1 Step -1
If R1(myRow).Value < Ignore Then
SpSum = SpSum + R2(myRow).Value
myCount = myCount + 1
If myCount = Pop Then Exit Function
End If
Next myRow

End Function



wrote in message
ups.com...
I made some metacode how it should look like but I need more VBA help

' CounterDay represents the columnnr where the calculation has to
happen. Starts on row 31 untill row 365
' CounterV is the counter to count the number of V's he finds (it
stops counting when CounterN has reached 30
' CounterN Is Increased by 1 when the cell A(DAY-1-CounterV) is equal
to the Value "V"

CounterDay = 31

IF A(DAY-1-CounterV) = V
Then CounterV = CounterV+1
Else CounterN = CounterN+1
End If CounterN = 30

Sum=B(CounterDay-1):B(CounterDay-CounterN)
Put Sum in Cell C CounterDay
CounterDay + 1

End If CounterDay=365