Changing height of existing animation

[FennShysa]

I'm making carpools out of existing custom drivable vehicles and I've noticed in certain cases (small dog, for one), when the dog is in the seat they stand on their hind legs and put their front paws on the dashboard. Cute, if there were a dashboard there. Instead I have a dog in an impossible position. So I thought I might replace the animation with a sitting pose. That works fine, except they are supposed to be sitting on the floor in the animation, so they actually end up under the seat. Is there a way with SimPE to adjust the height that they sit so that they are on the seat instead of under it? I see a z value in the animation and I'm tempted to change it except that it is different for dogs, cats, and small dogs, and that makes me wonder if it's the right thing to change.