Motion tracking between fingers

Hi everyone

First of all, I have tracked the tips of my fingers.

I am moving my thumb near to my forefinger. I want to create a lightning between them, coming out of the thumb when they are near. When I am moving them apart the lightning should dissapear. I kind like this:

I have no problems with creating the lightning. I don’t know how to make the lightning coming out of my thumb to the forefinger. The problem is the both fingers are moving a bit. So my main problem is creating a lightning from one moving empty project to an other moving empty project.

Thx for help