Spanish Manejar la orientacion de un texto

Dim S as String
S = "Hola Mundo"
S = S.Replace("o","0")    'S ahora vale "H0la Mund0"

Sub Reverse (S as String) As String
    Dim reverse As String
    reverse = ""
    For i = S.Length - 1 To 0 Step -1
        reverse = reverse & S.CharAt(i)
    Next
    Return reverse
End Sub

Sub ReverseUpDown (S as String)
    Dim Reverse as String
    Reverse = S
    Reverse = Reverse.Replace("a","ɐ")
    Reverse = Reverse.Replace("b","p")
    Reverse = Reverse.Replace("d","q")
    '... cambiar cada letra por la equivalente dada vuelta
    Return Reverse
End Sub