I went on the website to copy/paste:
Which is supposed to enable us to use the left and right triggers. However, I found that buttons 5 and 7 use the right bumper and the start button of the xbox controller, which means that the left and right triggers remain unused.
So, even though the xinput mapping is mostlycorrect (not the one on your website though, the one at the beginning of this post), the buttons R and L of the 3DS are assigned to the left and right bumpers of the xbox controller and the ZL and ZR buttons of the 3DS remain unassigned (since the xinput mapping of your website use the wrong buttons).
In short, I still can’t use the left and right triggers. I may have done something wrong and I’m completely off though ahah
Tried to correct it by myself thanks to: http://wiki.unity3d.com/index.php?title=Xbox360Controller but can’t seem to do it.