For the sake of your sanity, I beg you to reconsider. I’ve written code to read and write Excel files directly, but I wouldn’t touch a .doc file with a ten-foot pole.
Besides the hoplessly arcane format, you never know what your user will do (e.g. double-spacing, inserting images, using wildly different formats for different pages or paragraphs, using Fonts and type sizes instead of styles for headings, spaces for tabs -- the list is endless) and there are hundreds, if not thousands, of formatting codes you would need to recognize and convert to the relatively sparse entities in HTML.
In addition, Word is not designed for creating web pages and TinyMCE and FCK are. Word is essentially a poorly designed typesetting program that mixes content and formatting instructions together in an unholy salad -- the opposite of what HTML does.
If you’re determined to do it, take a look at some of the .doc to HTML conversion programs that are out there, but plan on manually editing most of the HTML files they produce.