Yes, and I understood perfectly. What I'm saying is that such a function is only useful between two animations. Sorry I wasn't very clear at all.
Often bones animation is a mixture of many animations (such as in vaio's example), but this only works if you reset the bones at the beginning of every frame, and so adding the extra parameter into ent_animate wouldn't have a previous animation to blend with.
I hope that makes sense.
Basically, you're asking for a very specific function, and as far as I can tell Rei has shown you how to do it. And like Pappenheimer says, what you're asking and vaio's example are two very different things.
And yes, what vaio is asking can be done in GS.
Jibb