Test InsTr vs InStrRev for VBA:

    Option Explicit

    Sub test()

        Dim testString As String
        testString = "123.456.789"

        Dim inStrIndex As Long
        inStrIndex = InStr(1, testString, ".")

        Dim inStrRevIndex As Long
        inStrRevIndex = InStrRev(testString, ".")

        Debug.Print "Find ""."" in """ & testString & """"
        Debug.Print "InStr: " & inStrIndex
        Debug.Print "InStrRev: " & inStrRevIndex

    End Sub


Output:

Find "." in "123.456.789"
InStr: 4
InStrRev: 8