Changing weapon animation?

Actually, any index from 0-255 can be used in either the 8 or 14 byte animations. Whether or not they'll produce the desired result is another story.
One thing to keep in mind is that the third animation slot works differently(it uses different locations) and is not compatible with animations designed for other slots(including the 8-byte animation slots) and vice versa.
In this specific example, putting the autocrossbow's animations into a weapon's will result in a correct animation, but the character doesn't take an initial step forward. This results in the character taking an unwanted step back, putting them behind their previous standing position. This will be the case with most animations from non-weapon abilities.
Unfortunately, I haven't done a lot of research into the deeper workings of animations, so I don't really know how to rectify this problem.
If one could figure out how to force a step forward, maybe a bit in the animation could be coded to signal to do so. But, I'm not sure where in the code things like stepping forward/backward are even done.