Pixel Plane and png sequences

Hi all....

I'm trying to position a png sequence on my mega tree....

I drop the sequence onto my MT PP and by changing the size of the individual PNGs that make up the sequence I can obtain 2 results. (1) with a 64x36 pixel sized PNG I get a huge picture taking up the entire height (60 pixels) of the tree or (2) with a 40x20 pixel sized PNG I get 3 seperate movies (all 3 playing) that are stacked one on top of the other but all 3 take up the entire height of the tree. I cannot seem to scale down the viewing area at all....

Is there some way to control the positioning of this sequence when I drop it into my PP as an external effect so that I can play it on specific section of the MT?

Thanks

SC