Just drop your HD clip composition into a pal comp, then right click on the layer in the comp panel and choose transform > fit to comp height (or width). You'll have to decide whether you want to lose either side of the element or have letterboxing.
The quality will be lower because pal sd has fewer pixels to work with. There's no real way of getting around this. However, the footage may
look worse than it will eventually look on tv if you have pixel aspect ratio correction toggled on because your monitor is showing the non-square pixels as square. Once you render it out it should look fine.
Simon Bonner
