I need to convert brush path to pen path?

I need the path not the outline of the brush stroke. So "expand appearance" or "create outline" is not a solution for me..

This is for a project with videoscribe (a software that turns svg's in to drawing animaitons) which needs contours to be pen paths.. But most of the time i get drawings which were made with brush tool from the artists..

So i had to redraw them.. is there a way to convert this.

Thx for any help