Function MySum(ByVal LenString As Integer, ParamArray sArr()) As Double
Dim I As Long, Cll As Range, Total As Double
For I = LBound(sArr) To UBound(sArr)
If TypeOf sArr(I) Is Range Then
For Each Cll In sArr(I).Cells
Total = Total + Cll.Value
Next Cll
Else...