horizontal alignment

Perhaps try:

Sub text_align()
With Selection
    Select Case .HorizontalAlignment
        Case -4108
            'center to right
            .HorizontalAlignment = -4152
        Case -4152
            'right to left
            .HorizontalAlignment = -4131
        Case Else
            .HorizontalAlignment = -4108
    End Select
End With
End Sub

though you might want to base the test on the first cell in the selection:

.Cells(1).HorizontalAlignment