p0rtalplayer wrote:
There's no good, dynamic way to do it. Various mappers have simulated the effects, like reepblue and HMW. I recall HMW posted a file with prefabs back on mAL, you could take a look at it.
Thanks, p0p. I don't know if this is gonna solve my problem, but I'll give it a try. But, like reep made in Blue Portals, some of these "solutions" are based on static portals, and I need using them with both portals. But don't worry. I'll not use those lasers so much, so this problem will not be repeated in much chambers.
p0rtalplayer wrote:
As there's no source code available for Portal, no source-code edits can be made, unfortunately. As for purely map-based solutions, Reep's and HMW's solutions are the best I've seen.
Ok, I'll try to make the best to hide it in my maps 
EDIT: Also, what of HMW's maps have this:

Because looks like these lasers don't need a static portal, and that's the only think I need for my map.
EDIT 2: Also, do you know somewhere to download a model to simulate those redirection cubes? I only need the model, I can make the entities by myself and parent them to the cube...
EDIT 3: Sorry for super-editing-mode, but I found a video that has this model that I need:
[yt:3muyufzw]http://www.youtube.com/watch?feature=player_embedded&v=bEiGfu1-0cA[/yt:3muyufzw]
I only need the model, or some model that looks like this 