Receive and control serial device data in visual basic - vb.net

Question

I have a serial device which sends me data at the baudrate of 38400 and i get it like this ?#D00014C000 000. I can see data comes in on a ritchtextbox but what im trying to do is to use some characters from the string in a list box.
For example i want characters "14C" appears in the listbox3. I tried the substring and mid function but listbox lidnt work properly and losses characters or confuse them . Here is my code. Any suggestions please??
Imports System
Imports System.ComponentModel
Imports System.Threading
Imports System.IO.Ports
Public Class frmMain
Dim myPort As Array
Delegate Sub SetTextCallback(ByVal [text] As String)
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
ReceivedText(SerialPort1.ReadExisting())
End Sub
Private Sub ReceivedText(ByVal [text] As String)
If Me.rtbReceived.InvokeRequired Then
Dim x As New SetTextCallback(AddressOf ReceivedText)
Me.Invoke(x, New Object() {(text)})
Else
Me.rtbReceived.Text &= [text]
Dim fine As String = Mid([text], 7, 3)
Dim list As Integer = ListBox3.Items.Add(fine)
End If
End Sub
End Class
Here isPICTURE 1 what happens
Picture2