I'm trying to make a stab animation in MS. I can do it no problem except I can't get the end part of the hands to go w/ the joints. When the animation plays. Part of the hands stay still while the rest move, creating a paper thin arm w/ a normal hand. How can I assign the entire hands models tothe joints or fix this?

Also, i'm, trying to get it so he hold it normaly before he stabs but I cant figure out how to make the whole thing be in he right place. I'm trying to make it so the animation doesn't "jump" into place if u understand waht I mean.

You assign vertices to joints by going to the joints tab on the main panel. Select the bone you want from the list (just click on it), then select the vertices that you want assigned to it. Unfortunately this is a fairly tedious process and if you don't do it right it ends up looking like crap. I suggest going off of the default assignments.

I think what you mean is that you want to have the first frame be him holding it normally (like in his idle position) and then he makes his stabbing motion. I would suggest you copy the keyframe of your default position, but also don't forget that HL will interpolate between frames. That means that if you have 1 frame be the default, and the next it's all the way extended, HL will try to make it smoothly transition.