Hi,
You don't really need runtime interpreter to achieve this. PlayMaker and its set of action can do that already actually.I have made an working example attached to this post.
basically, you take the mouse position, you convert it into world coordinates, BUT you have to set the right z value ( which is the distance from the camera, so in your case, I assume the gameObject that looks at the mouse is at 0,0,0, so I only need to get the camera z distance and invert it)
then, I have a world position to look at.
If you have questions, let me know.
Bye,
Jean