How can I perform an operation in excel vba for an user-defined range?

Question

I have a series of cells with values ie

I would like to have a for loop that is doing the average of the first value in column A (1), the adjacent value in column B (3) and the adjacent value in column C (74). I would need the user to choose this range with a msgbox.

So far I could code this, with the help from the macro recording:

Sub averager()
    Dim ran As Range, average As Variant, cell1 As Variant, cell2 As Variant
    Dim i As Variant

    Set ran = Application.InputBox(Prompt:="Enter range values: ", Type:=8)

    For i = 0 To i = 8
        ran.Offset(0, 13).Select
        ActiveCell.FormulaR1C1 = "=AVERAGE(RC[-13]:RC[-11])"
        average = WorksheetFunction.average(ran.Text)
    Next i
End Sub

However, this code doesn't perform the loop and it returns only the first triplicate's average in the offset position I chose.

How can the loop perform the operation for all the values?

Answer 1

1. Catch the error in case the user presses the Cancel button.
2. You don't need a loop, you can write the formula to multiple cells at once.

---

Option Explicit

Public Sub Averager()        
    Dim ValueRange As Range
    On Error Resume Next 'if user presses cancel this throws an error
    Set ValueRange = Application.InputBox(Prompt:="Select range values: ", Type:=8)
    On Error GoTo 0

    If Not ValueRange Is Nothing Then
        ValueRange.Offset(ColumnOffset:=6).Resize(ColumnSize:=1).FormulaR1C1 = "=AVERAGE(RC[-6]:RC[-4])"
    End If
End Sub