[Vit]

Сам нашел вариант, может несколько корявый, но вполне рабочий.
procedure TForm1.N10Click(Sender: TObject);
var
k:TTreeNode;
begin
if TreeView1.Visible=true then
TreeView1.Visible:=false;
F := TFileStream.Create('C:\GLB\izd\TV.txt', fmOpenRead or fmShareDenyWrite);
try
F.ReadComponent(TreeView1);
finally
F.Free;
end;
TreeView1.Visible:=true;
TreeView1.Selected := GetNodeInPath(PChar(DBEdit1.Text+'\'+DBEdit2.Text) , '\', TreeView1);
k:=TreeView1.Selected;
TreeView1.Items.AddChild(k,'ТЗ.dwg');
k.Expanded:=true;
TreeView1.Selected := GetNodeInPath(PChar(DBEdit1.Text+'\'+DBEdit2.Text+ '\ТЗ.dwg'), '\', TreeView1);
TreeView1.Selected.SelectedIndex:=1;
Button2.Click;
F := TFileStream.Create('C:\GLB\izd\TV.txt', fmCreate or fmShareCompat);
try
F.WriteComponent(TreeView1);
finally
F.Free;
end;
TreeView1.Visible:=false;
TreeView1.Visible:=true;
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
if TreeView1.Selected.SelectedIndex=1 then
TreeView1.Selected.ImageIndex:=1;
end;

end.