Imports System

Public Module Module1

    Public Sub Main()

        Dim _XML As String = ""

        Dim _xmlSend As String = "<EFF_DATE>20181010</EFF_DATE><EXP_DATE>20191010</EXP_DATE>"

        Dim start_Index_EFF_DATE As Integer = _xmlSend.IndexOf("<EFF_DATE>") + 9

        Dim end_Index_EFF_DATE As Integer = _xmlSend.IndexOf("</EFF_DATE>") - 1

        Dim index_EFF_DATE As Integer = (start_Index_EFF_DATE - end_Index_EFF_DATE)

        Dim effDate = _xmlSend.Substring(index_EFF_DATE, 8)

​

        Dim start_Index_EXP_DATE = _xmlSend.IndexOf("<EXP_DATE>") + 9

        Dim expDate = _xmlSend.Substring(start_Index_EXP_DATE, 8)

        Console.WriteLine("Result => " & end_Index_EFF_DATE)

    End Sub

End Module