Dreamweaver 4 help with layers needed

How do I make a layer relative to a table cell? The page had already been designed (by someone else) and was originally left justified, so the absolute positioning worked fine. Now I've been asked to center the page in the browser and I need to know how I can get the layers to move along with the rest of the page. The reference book that I've been given tells me this is possible, but doesn't give any specifics.

I'm new to using Dreamweaver and this has me stumped even though it's probably easy to do. Any help would be greatly appreciated, or, point me to a page using relative positioning of layers so I can study the code.