How to track paint strokes to video in Motion 5?

Hi All,

I have a video clip of me in front of the camera, drawing my name in the air with my finger. I would like to be able to make a paint stroke follow my finger and draw out my name. Because there is a lot of motion blur, I cannot motion-track my finger automatically. I just don't know how to paint the stroke in the exact place I need it. Can anyone help me to figure this out?

Thanks,

Adam