Blood Smear Following a Motiong

What's wrong with animating a bunch of masks and pinning your blood into place with tracking?

Mylenium 

You'll need to rotoscope the hand and use that as a track matte to reveal the blood smear placed above the object in the scene that is supposed to have the smear. Mocha AE is probably the best tool to do that kind of Rotoscoping.

If that's not it, we need a detailed description of the shot and/or an embedded by dragging or copy-and-paste instead of attaching a screenshot so we can see it without downloading it.