サンプルマクロは、アクティヴシートのＡ１の文字列を逆転させます。

Sub Sample()

    Dim myStr As String
    Dim myLetter As String
    Dim i As Integer
    
    i = Len(Range("A1").Value) + 1
    While i > 1
        i = i - 1
        myLetter = Mid(Range("A1").Value, i, 1)
        Select Case StrConv(myLetter, vbWide)
            Case "゛", "゜"
                i = i - 1
                myLetter = Mid(Range("A1").Value, i, 2)
        End Select
        myStr = myStr & myLetter
    Wend
    
    Range("A1").Value = myStr

End Sub