Как к узлам дерева прикрутить структуру struct Card?

private void Serialize()
{
    using (FileStream fs = new FileStream("d:/tree.ini", FileMode.OpenOrCreate, FileAccess.Write))
    {
        BinaryFormatter bf = new BinaryFormatter();
        bf.Serialize(fs, treeView1.Nodes.Cast<TreeNode>().ToList());
        fs.Close();
    }
}

private void Load()
{
    if (File.Exists("d:/tree.ini"))
    {
        using (FileStream fs = new FileStream("d:/tree.ini", FileMode.OpenOrCreate, FileAccess.Read))
        {
            BinaryFormatter bf = new BinaryFormatter();
            treeView1.Nodes.Clear();
            object obj = bf.Deserialize(fs);
            TreeNode[] nodeList = (obj as IEnumerable<TreeNode>).ToArray();
            treeView1.Nodes.AddRange(nodeList);
            fs.Close();
        }
    }
}

Cards = new List<Card>();
I = Cards.Count - 1;
Cards[I].N = TN.Nodes[i].Handle;
...

TreeNode TN = new TreeNode();
TN = treeView1.SelectedNode;
List<TreeNode> Del = new List<TreeNode>();
Del.AddRange(TN.Nodes.Cast<TreeNode>().ToArray());

while (TN.Nodes.Count != 0) TN = TN.Nodes[0];
if (TN.Tag == null) { TN.Remove(); continue; }
TN = TN.Parent; Val = TN.GetNodeCount(false);
for (j = 0; j < Val; j++)
    if (TN.Nodes[0].Tag != null && TN.Nodes[0].GetNodeCount(false) == 0) { 
        Del.Insert(Del.Count, TN.Nodes[0]); TN.Nodes[0].Remove();
    }