Windowshape image as mask for second image

[Sivakatirswami]

I have this "concept" and I'm not really sure it can be implemented  
in Rev... at least I haven't found a way:

1) Establish a border that is like a picture frame, that is feathered  
on the outer edges... and the inside is transparent....

2) use this as a windowshape

3) next we want to place an image inside this "frame" such that the  
frame serves as a mask to the second image which is underneath...  
then we would want the image underneath to be set to move across very  
slowly... but only appear on the inside of the frame.

Now, this doesn't work...

Saving the window frame as PNG with transparency on.. we get a lowly  
frame, and I can see right three the middle to my desktop and also  
the outer edges are feathered. Lovely: caveat: the inside of the  
frame is also completely knocking on the entire interface!

any ideas... am I making sense?

I think I may need to redo that windowshape image so that it is solid  
in the center and then put some other kind of images on top... like  
another png image that serves as a clipping path for an image  
underneath it... how do you do that?

Is it possible how to set the mask data or one image to the pixel  
values of another image? If you do this... can you have the image  
move around inside the mask (i.e. the mask is like a clipping path,  
that is static, but the image can move around inside it under script  
control) i.e. I

These are the kinds of things we hope will be easier in future  
versions of Rev....I need to see example scripts or stacks as I'm not  
able to, from the documentation, actually do anything....

Sivakatirswami