'This Macro will reverse a selection of rows or columns.
'Note: you cannot select an etire row or column, but one
'cell less than that will work fine.
'Don't forget to assign this macro a keyboard shortcut or
'a toolbar button.

Dim Arr() As Variant
Dim Rng As Range
Dim C As Range
Dim Rw As Long
Dim Cl As Long

On Error GoTo EndMacro

Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
Application.EnableEvents = False

Set Rng = Selection
Rw = Selection.Rows.Count
Cl = Selection.Columns.Count
If Rw > 1 And Cl > 1 Then
MsgBox "Must select either a range of rows or columns, but not simultaneaously columns and rows.", _
vbExclamation, "Reverse Rows or Columns"
Exit Sub
End If

If Rng.Cells.Count = ActiveCell.EntireRow.Cells.Count Then
MsgBox "Can't select an entire row, only up to one cell less than an entire row.", vbExclamation, _
"Reverse Rows or Columns"
Exit Sub
End If
If Rng.Cells.Count = ActiveCell.EntireColumn.Cells.Count Then
MsgBox "Can't select an entire column, only up to one cell less than an entire column.", vbExclamation, _
"Reverse Rows or Columns"
Exit Sub
End If

If Rw > 1 Then
ReDim Arr(Rw)
Else
ReDim Arr(Cl)
End If

Rw = 0
For Each C In Rng
Arr(Rw) = C.Formula
Rw = Rw + 1
Next C

Rw = Rw - 1
For Each C In Rng
C.Formula = Arr(Rw)
Rw = Rw - 1
Next C

EndMacro:
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
Application.EnableEvents = True

End Sub