If it can help anyone, I just found a solution.
Create a "num" variable for the 3D object and the sprite. From the layout, for each 3D object, create a sprite and give the same number to the 3D object and the sprite. Associate the sprite to the face of the 3D object.
Then to control the animation of the sprite, just pick by comparing the variable "num" of the 3D object and the sprite.
I don't know if this method is optimal.. but it works ^^