thanx a lot guys, i got it!
my mistake was that i applied a brushstroke to the path in illustrator, and then coppied the brush,which is in fact very much masks, that confused me because i had circa 100 masks in ae.
the right way is to copy only the path in illusrtator(so you get one path)and bring this one to ae, then it works, as you said guys!
thanxs for the great forum(im from austria, greatful to get some prof. help)