Der Code für ein allgemeines Modul:
Public Function Addition(ByVal rngBereich As Range) As Long
Dim Zelle As Range
Dim SPL
Dim lngX As Long
For Each Zelle In rngBereich
SPL = Split(Zelle, ",")
For lngX = 0 To UBound(SPL)
Addition = Addition + Val(SPL(lngX))
Next
Next
End Function