Android Question How to get items in customlistview?

Sub Globals
    Private Mainlist As CustomListView
end sub

Sub Activity_Create(FirstTime As Boolean)
Dim cursor1 As Cursor

Activity.LoadLayout("Layout1")

cursor1 = Main.SQLDB.ExecQuery("SELECT DISTINCT ARTGROEP.GRPNR, ARTGROEP.GRPOMS FROM ARTGROEP ORDER BY ID ASC;")
If (cursor1.RowCount > 0) Then
    cursor1.Position = 0
    For i = 0 To cursor1.RowCount - 1
        cursor1.Position = i
        MainList.Add(MainItem(cursor1.GetString("GRPOMS").Trim),cursor1.GetString("GRPNR").trim)
    Next
End If
cursor1.Close

End Sub

Sub MainItem (txt As String) As B4XView
    Dim p As B4XView = xui.CreatePanel("Panel")
    Dim  TargetDir As String

    If File.ExternalWritable Then TargetDir = File.DirDefaultExternal Else TargetDir = File.DirInternal
    
    p.SetLayoutAnimated(0, 0, 0,MainList.AsView.Width,MainList.AsView.Height/3)
    p.LoadLayout("item")
    
    Label0.Color = Colors.White  ''Transparent
    Label0.TextColor = Colors.black
    Label0.TextSize = 18
    Label0.Top = Imageview0.Height - 5%y
    Label0.Left = 2%x
    Label0.Width = 15%x
    Label0.Height = 4%y
    
    If (File.Exists(TargetDir & "/PICTURES/GROEP",txt & ".JPG") = True) Then
        Imageview0.Bitmap = xui.LoadBitmapResize(TargetDir & "/PICTURES/GROEP", txt & ".JPG",Imageview0.Width,Imageview0.Height,True)
    End If
    Label0.Text = txt
    
    Return p
End Sub

Sub MainList_ItemClick (Index As Int, Value As Object)
'' here i go to another screen.
'' showing picture and changing text
'' after that going back to customlist, not rebuilding but only
'' corresponding label0.text has to be changed.
end sub

Sub Globals
    Private Mainlist As CustomListView
    Public TargetLabel as Label
end sub

Sub MainList_ItemClick (Index As Int, Value As Object)
   Dim p as Panel = MainList.Getpanel(index)
   TargetLabel = p.GetView(0) 'This can be wrong without knowing you View Tree of the Layout
   'Open your modification page and assign the new text to TargetLabel.Text
end sub