ListBox - finding specific data and index

[JeezyWonder]

Hello everyone, what i'm doing now, it's read info from CANBUS and put it in the listbox in vb6. It looks like

 tmp = idtag.Text & vbTab & dlc.Text & vbTab & RxData.Text

SO what i have in listbox after a get it its
so as you can see i have two id 140, so it means listbox just add new line every time. What i want it's make it read ID then if its equal to id that we receive from CANBUS, we put data exactly to that ID. Like "if ID from CANBUS = ID in LISTBOX then update data from CANBUS in that ID, if received id doesnt excist in listbox, then add new item". As you can see from a picture i recevie data from canbus in one like, ID+DLC+DATA like this "0000014008BBBBBBBBBBBBBBBB" then i extract right values from with MID() then add to listbox. My code is:

Select Case MSComm1.CommEvent
    Case comEvReceive
    Buffer = MSComm1.Input
    Text1.Text = Text1.Text & Buffer
    If Len(Text1.Text) = 26 Then
    Text4 = Text1
        idtag.Text = Mid(Text1.Text, 6, 3)
        dlc.Text = Mid(Text1.Text, 10, 1)
        RxData.Text = Mid(Text1.Text, 11, 16)
        'Call Command1_Click
        RxData.Text = Right(Text1.Text, Val(dlc.Text * 2))
        RxData = SpaceIt(RxData)
        tmp = idtag.Text & vbTab & dlc.Text & vbTab & RxData.Text
        If List1.ListCount > 14 Then List1.RemoveItem (a)
        List1.AddItem tmp, a
        Text1.Text = ""
        a = a + 1
        If a > 14 Then
            'List1.Clear
            a = 0
        End If
    End If
End Select
End Sub

Any ideas? aprecciate any input. Thanks