creating an unusually shaped mask

[dsdsdsdsd]

hello;

this is not a AS3 question, but a general flash question;

I am masking a rope shape over 100 frames ( for a preloader );

currently I have about 70 keyframes in place over the 100 frames to make the mask suitably unmask the rope-shape;

is there a better way to make a mask follow some non-uniform tween, such as the shape of a curvy rope?


thanks,
dsdsdsdsd