I saw an old topic, but if I follow the link, I only get trainers for the Retail versions of the game.
Who can show me the place to download this trainer (if it exists)?
Yep, all CH trainers are designed for the Retail version only.
There may be a site like GCW that has trainers for the Steam version, but I don't know if they work, and I think I'm not allowed to link you to them because the site also features no-cd fixes.
But, it's easy enough to find. Just go to google and type: "Left 4 dead 2 steam trainer" and voilá.
[Edited by Monkey007, 1/5/2012 5:30:28 PM]
[Edited by Monkey007, 1/5/2012 5:30:40 PM]