I can't write this stuff off the top of my head. I have to write and then see how it behaves, then modify until I get it right. Maybe I can get you started.
To the css file add a new div declaration where the X and Y in the example are modified to the numbers you want.
Then in your html add the part just above the closing body tag:
<div id="newdiv"> <!-- Opens the new div-->
add your script here
</div> <!-- closes the new div-->
Now you may or may not have to clear some floats to make that work.