<div style="position:relative; border:2px solid black; height:200px; width:410px">
<div style="height:200px;background-color:lime;position:absolute;left:0;top:0;width:200px"></div>
<div style="height:200px;background-color:lime;position:absolute;right:0;top:0;width:200px"></div>
<div style="position:absolute;height:200px;width:300px;background-color:lightgray; left:200px; top:200px;">
This text should be outside the columns.<br>
This text should be outside the columns.<br>
This text should be outside the columns.<br>
This text should be outside the columns.<br>
This text should be outside the columns.<br>
</div>
</div>
</div>