integration with personal site

Hello,

Im new to wordpress and have been searching the webz trying to find an answer to my question that i cant come up with.

i already have an up and running site that had a pure HTML blog. (type and post via server access) im now switching to wordpress to gain the ease and freedom.

my site currently is:

————-header———-
Nav bar——–content——-
————-footer———-

i want to take the needed codes from WP so that i can use the layout i have now and just add the WP content (all posts) and the WP side bar to my current content section.

so my site would be
———–Personal header———-
Person navi — WP posts —WP sidebar
———–Personal footer———–

im looking to do this with no theme/css from WP as it should all be using my personal CSS already setup and just drop it into my content DIV so i dont think a theme would be needed.

am i asking too much?

thanks!