Using range references as parameters for user-defined functions

The previous example of calculating the cost of a batch of books is already quite convincing. VBA can indeed make a user’s life easier.

One question arises from the two examples given. In the user-defined functions created, the parameter values were only cell references. Is it possible to create a user-defined function where the parameter values can be references to a range of cells?

Function MySum(ByVal rng As Range) As Double
    Dim c As Range
    Dim s As Double
    s = 0
    For Each c In rng.Cells
        s = s + c.Value
    Next
    MySum = s
End Function

The code demonstrates the use of range references and solves the task of summing values in a specified range of cells (see also the file 1-UserFunctions.xlsm on the CD).