Internet Explorer bug

Our college office website contains a page with a list of school administrators. The list has to be updated pretty frequently, and I wanted to make it easy on our secretary. So I set it up that whenever she updates the main Excel records containing the names, all she has to do then is save the Excel sheet in html format and post it to our server. The html formatted list of names is then inserted as an object into the office website Administration page. That is, the Administration page calls the html-formatted Excel list. The reason it's necessary to do this is because the Administration page is formatted to look like the rest of our site, while the html-formatted Excel list is just a plain looking document. So we have the list of names called by the Administration page simply so it looks good. However, I discovered that although this works fine in Firefox, Internet Explorer has a z-index bug, and consequently when the full Administration page is viewed in IE, the inserted list page appears on TOP of the site's roll-out menu. That is, in IE the inserted page obscures the menu. So what we're looking for is a solution that we can either include in the body html of the Administration page or in our css file that will make it so the inserted page appears BEHIND the main page's menu roll-out as it should.