Can you find out if your server supports server side includes (SSI)?
If they do, you can put the information in another html file and reference it from the page where you want it to display.
On my sites, I have a folder set up called "includes" and in it I have files that contain the stuff I want to insert. These files are saved as html files, but you don't need the <html>, <head>, <body> tags, etc. Just put whatever you want to appear on the page.
One of my includes holds that little bit of text I keep on the bottom of each page saying "this site designed and maintained by..." - I called it "design.html". clever name, huh?
Anyway, wherever I want that information to appear, I just insert the following code:
<!--#include virtual="../includes/design.html" -->
Or something approximately similar. (like of course I don't use the ../ if I don't need to go up in the directory structure to get to the includes folder.)
A couple things you have to do to make this work, besides making sure your server supports it at all:
Be aware that if no adjustments are made, includes will not work on html pages. I'm not talking about the fact that the include pages themselves are html files - that's ok. I'm talking about the pages where you want to insert the include's content.
They will work on shtml files, so one option is to change your extensions to shtml. There are problems with this, especially since you're talking about your main page. Even on secondary pages, if you've got the page up already you probably don't want to go changing the names. People may be looking for certain pages by the old name, and you don't want to lose anyone.
Another option is editing what's called your htaccess file so that includes *will* work in html files. (or asking support at your host to do it) This may be too heavy, but in case you venture in that direction, your main directory needs a file called .htaccess (right - nothing before the dot) which need a line in it that reads
AddHandler server-parsed .html
(again, no tags or anything, just that.)
Well this was probably more than you wanted to hear, huh? I hope you can get the SSI stuff going - it's really a great tool. I've got a million pages (well not a million, but it felt like it when I was hand coding every one every time I changed my email address...) but anyway, for example, if I want to change my contact information, I don't have to edit every page where I want it to display. Now that I have it set up to just call on an include, I just go in and change the include - *once*. (of course you have to put the includes there in the first place, but well, we wanted to do web design

)
Ok, I think that's all (!)
Good luck,
AmyD