Random selection of values from a list and randomization of the values

Sub Strawbales()
     Dim cSource, cDest, aSource, aDest()
     Set cSource = Range("F18:F42"): aSource = cSource.Value
     Set cDest = Range("G18:G42"): ReDim aDest(1 To cDest.Rows.Count, 1 To 1)

     i = InputBox("Give a number between 1 and " & cSource.Rows.Count & vbLf & "0 = stop", "Wanted values", 1)
     If Not IsNumeric(i) Then MsgBox "error": Exit Sub
     If i = 0 Then Exit Sub
     If Not (1 <= i And i <= UBound(aSource)) Then MsgBox "wrong number": Exit Sub

     seq = [column(a1:aaa1)]     'sequence 1,2,3,....
     ptr = i     'pointer
     For j = 1 To i
          r = Application.RandBetween(1, ptr)     'random choice between "remaining" elements
          aDest(j, 1) = aSource(seq(r), 1)     'take that random choice
          seq(r) = seq(ptr)     'move last remaining element to this position
          ptr = ptr - 1     'number of remaining elements
     Next
     cDest.Value = aDest     'copy array to range

End Sub