I'm just kidding bro
Some how I got it to work (some times I even amaze myself

).
If you are using an other sword model, you need to change this two numbers according to your sword model:
vec_for_vertex(trailpos2,me,39); // vertex at the top of the sword
vec_for_vertex(trailpos1,me,9); // vertex at the bottom of the sword
Results...
BEFORE:
AFTER:
I hope, this is what you were looking for
