I'm not sure if what your asking can even be done. I have never heard or seen this, but even if you could do this, why? What a nightmare for your visitors to deal with. It sounds to me that you need to get into some sort of HTML editor program that will give you more freedom over controlling the layout of your webs pages, since I am assuming that you are using Freewebs, or similar program. The structure of a web page can be controlled to a greater extent with an editor program and will free you from the limitations that you now face. Maybe you're ready for the next step. An HTML editor will also teach you a lot about proper web page layout.

here's a good place to start: http://www.coffeecup.com/html-editor/

Happy web building