Reading from a Serial Port output start byte

[neerajsundriyal]

Imports System.IO.Ports

Public Class serial_chat

    Delegate Sub OutputTextBack(ByVal [text] As String)

    Private Sub serial_chat_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        For Each port In IO.Ports.SerialPort.GetPortNames
            ComboBox1.Items.Add(port)

        Next
    End Sub

    Private Sub Connect_Click(sender As Object, e As EventArgs) Handles Connect.Click
        Try
            If Connect.Text = "Connect" Then
                SerialPort2.PortName = ComboBox1.SelectedItem.ToString()
                SerialPort2.Open()
                GroupBox2.Enabled = True
                ComboBox1.Enabled = False
            Else
                SerialPort2.Close()
                GroupBox2.Enabled = False
                Connect.Text = "Connect"

            End If
        Catch ex As Exception
            MessageBox.Show(ex.Message)

        End Try
    End Sub

    Private Sub Send_Click(sender As Object, e As EventArgs) Handles Send.Click
        Try
            SerialPort2.Write(TextBox1.Text & vbCr)
            RichTextBox1.Text += "Me : " & TextBox1.Text & vbCr
            TextBox1.Clear()

        Catch ex As Exception
            MessageBox.Show(ex.Message)

        End Try
    End Sub

    Private Sub SerialPort1_DataReceived(sender As Object, e As SerialDataReceivedEventArgs) Handles SerialPort2.DataReceived
       
        Receivedtext(SerialPort2.ReadExisting())

    End Sub
    Sub UpdateReceviedText()

        Dim bytes As String = SerialPort2.BytesToRead
        Dim buffer As String = SerialPort2.BytesToRead
            buffer = SerialPort2.ReadExisting()
            bytes = SerialPort2.ReadExisting()

        If Mid(bytes, 1, buffer) = " me :  # - !" Then
            SerialPort2.Write("Ok")
        End If

    End Sub

    Private Sub Receivedtext(ByVal [Text] As String)

        If Me.RichTextBox1.InvokeRequired Then
            Dim x As New OutputTextBack(AddressOf UpdateReceviedText)
            Me.Invoke(x, New Object() {(Text)})
        Else
            Me.RichTextBox1.Text &= [Text] & vbCrLf
        End If
    End Sub
End Class

i want my serial port start bit read should be "#" and end with "!" when it get both character in text form ,then it should received ok message in terminal or virtual com serial port.
Please help its my task and i am newbee vb programmer.Kind ly revert ASAP.