[ns] problem working with manual routing

[pdommay@ribera.tel.uva.es]

Hi all!!

I'm doing my Ends Career Proyect with Matlab and i need to use ns 
to do some simple simulations. Unfortunately i'm new on it. I want 
to work with Manual Routing, over wired networks. I've read the 
Marc Greis's tutorial and the NS for Beginners tutorial but they 
don't talk about it :(, and the Manual just includes a simple 
paragraph of it and i don't manage to run my simulation just with 
it. My first example is quite simple:

I have four nodes

   n0 ------ n1
   |         |
   |         |
   |         |
   n2 ------ n3

and i want to send information between nodes n0-n1 but going 
through nodes n2 and n3.

I've seen there exists the commands "add-route-to-adj-node $node" 
and "add-route $node_dest $next_hop", but i don't find how to use 
them, neither in the documentation, nor at the ns mail list, and i 
don't understand quite well the example many_tcp.tcl

Can anyone help me please???

Thanks for any information you can give me :).

Pablo.