css, div tags and redefing web page focus

[bergenpeak]

I've got loads of existing web pages (vanilla html, html + frames,
etc) and 100s of non html files (just raw text).

I'd like to wrap these pages with the classic navigation format and
info. Logically, there would be three "panes" of info in the
browser-- the header info, the left nvigation info and then the
"content" portion of the window where all web page changes are
displayed.

I've defined the css for the top navigation page, the left navigation
pain and the main contnet page using "div" tags.

Is there a way to define the "content" pane to be where all web page
loads happen? For instance, if in the left navigation pan, I had a
link for "cnn.com", and this link was clicked, I would like the
cnn.com page to load in the "content" pane and not load into the
entire window. I want the top and left navigation information to
remain in the browser.

Is there a way to set something in the "content" pane portion of the
css so that all web page updates are in this pane.

Thanks