I need to know if it is possible to establish some kind of index / key to those nodes, the problem arises because I need to be able to create more accounts and if I have two accounts with the same name I need to know their exact location (the accounts that I have parents and daughters).
So if anyone has any idea or suggestion, welcome it.
You can use the property .Tag that has the TreeNode object. My recommendation would be that you use unique integers as identifiers, but seeing your TreeView I imagine that they come from different tables so it may be convenient to use pipe lines (|) to separate the Identifiers and then resume them with a split in this way:
TreeNode tnActivo = new TreeNode();
tnActivo.Text = "ACTIVO";
tnActivo.Tag = "1";
TreeNode tnActivoCorriente = new TreeNode();
tnActivoCorriente.Text = "ACTIVO CORRIENTE";
tnActivoCorriente.Tag = "1|1";
TreeNode tnCaja = new TreeNode();
tnCaja.Text = "CAJA";
tnCaja.Tag = "1|1|1";
TreeNode tnBancos = new TreeNode();
tnBancos.Text = "BANCOS";
tnBancos.Tag = "1|1|2";
tnActivoCorriente.Nodes.Add(tnCaja);
tnActivoCorriente.Nodes.Add(tnBancos);
TreeNode tnActivoNoCorriente = new TreeNode();
tnActivoNoCorriente.Text = "ACTIVO NO CORRIENTE";
tnActivoNoCorriente.Tag = "1|2";
tnActivo.Nodes.Add(tnActivoNoCorriente);
tnActivo.Nodes.Add(tnActivoCorriente);
And to recover them you can use
string[] identificador = tnBancos.Tag.ToString().Split('|');
//DONDE identificador[0] = 1
//DONDE identificador[1] = 1
//DONDE identificador[2] = 2