Склонение фамилий в программе, способы реализации - VB

Function DativeCase(sSurname$, Optional sName$, Optional sPatronymic$) As String
 
    Application.Volatile True
    On Error Resume Next
    If sName$ = "" And sPatronymic$ = "" Then
        arr = Split(Application.Trim(sSurname$))
        sSurname$ = arr(0): sName$ = arr(1): sPatronymic$ = arr(2)
    End If
 
    Dim bMaleSex As Boolean: bMaleSex = (Right(sPatronymic, 1) = "ч")
 
    If Len(sSurname) > 0 Then    
        If bMaleSex Then
            Select Case Right(sSurname, 1)
                Case "о", "и", "я", "а": DativeCase = sSurname
                Case "й": DativeCase = Mid(sSurname, 1, Len(sSurname) - 2) + "ому"
                Case Else: DativeCase = sSurname + "у"
                 If bMaleSex Then
                    Select Case (sSurname)
                        Case "паршивлюк", "хомяк": DativeCase = sSurname
                    End Select
                End If
            End Select
        Else
            Select Case Right(sSurname, 1)
                Case "о", "и", "б", "в", "г", "д", "ж", "з", "к", "л", "м", "н", "п", _
                     "р", "с", "т", "ф", "х", "ц", "ч", "ш", "щ", "ь": DativeCase = sSurname
                Case "я": DativeCase = Mid(sSurname, 1, Len(sSurname) - 2) & "ой"
                Case Else: DativeCase = Mid(sSurname, 1, Len(sSurname) - 1) & "ой"
            End Select
        End If
        DativeCase = DativeCase & " "
    End If
 
    If Len(sName) > 0 Then    
        If bMaleSex Then
            Select Case Right(sName, 1)
                Case "й", "ь": DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 1) & "ю"
                Case "л": DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 2) & "лу"
                Case "я": DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 1) & "е"
                Case Else: DativeCase = DativeCase & sName & "у"
            End Select
        Else
            Select Case Right(sName, 1)
                Case "а", "я"
                    If Mid(sName, Len(sName) - 1, 1) = "и" Then
                        DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 1) & "и"
                    Else
                        DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 1) & "е"
                    End If
                Case "ь": DativeCase = DativeCase & Mid(sName, 1, Len(sName) - 1) & "и"
                Case Else: DativeCase = DativeCase & sName
            End Select
        End If
        DativeCase = DativeCase & " "
    End If
 
    If Len(sPatronymic) > 0 Then    
        If bMaleSex Then
            DativeCase = DativeCase & sPatronymic & "у"
        Else
            DativeCase = DativeCase & Mid(sPatronymic, 1, Len(sPatronymic) - 1) & "е"
        End If
    End If
End Function

                 If bMaleSex Then
                    Select Case (sSurname)
                        Case "паршивлюк", "хомяк": DativeCase = sSurname
                    End Select
                 End If