[Gtk-sharp-list] Update row cells

[Toño]

Hi all,
It's the first time I post in a mailing-list... I hope to do it well.
My problem is I have a Gtk.Treeview. I have added some columns. I have
added some rows. But what I want is to modify a row cell. For
instance...

Name          	Place           Speed
=========================================
John         	London	        34kbps
Bill            London          12kbps
John         	New York	45kbps

What I want is to modify the speed cell of each row. Names or places can
be the same so... I have to identify the row object somehow.
In WinForms I could use row.Tag = Objet to identify my objet, but I'm
not sure how to do it in Gtk.

Kind regards

PD: Sorry for my english