How can I alpha an animation in the library?

I’m trying to make a fading in and out effect using alpha and motion tween. But I can only do it in my working stage, (the scenes). I can’t do it in my library. I need to do it in the library as it is an animation for my button… Anyone willing to help?

select the frames on your main stage.

use menu option “Edit/Copy Frames”, then “Edit/Cut Frames”.

Use menu option “Insert/Create New object”. Choose Movie Clip from the options.

A new timeline will come up.
Select frame one, and use menu option, “Edit/Paste Frames”.

You now have a movie clip of whatever you did on the main timeline.

Much thanks…