liquid navbar

I have a horizontal navbar between my banner and the page's main
content (divided into three columns). Below the navbar, the left and
right columns are fixed and the center is liquid. I want to position
the navbar "li"s directly above the center column and make them liquid
so they stretch and contract in correspondence with the center column.
Is there a way to do this?

Thanks.

The styling I'm working with now is:

#navcontainer {
position:absolute;
left:0px;
z-index:1;
width: 76% ;
background-color: fuchsia; }

#navcontainer ul {
border: 0;
padding: 0;
list-style-type: none;
margin-left: 200px;
text-align: center; }

#navcontainer li {
display: block;
float: left;
text-align: center;
padding: 0;
margin: 0;
}

#navcontainer ul li a {
background: #669999;
width: 50px;
height: 18px;
padding: 0;
margin: 0;
color: #FFF;
text-decoration: none;
display: block;
text-align: center;
font: normal 10px/18px "Lucida Grande", "Lucida Sans Unicode",
verdana, lucida, sans-serif; }