Is there a way? Yes
Is there a simple clean way? No. At least not until the next version of CSS becomes widely adopted.
Basically, there are several methods people use to make rounded corners.
If you know that the width and height of your container is never going to change, the easiest method is to create a box with rounded corners in a photo editing program such as Photoshop, making the backgound color in Photoshop the same color as the background on your page, in your case white. The dimensions also need to be the same pixel height and width as your container.
Then save that image and use it as the backround of the container
#containerID { /or whatever the container name is/
background: url(../images/your_image_name.jpg) top left no-repeat;
}
If your container is going to vary in size dynamically according to the layout, then if using background images, your stuck with creating additional containers inside the main container and adding small corner background images using absolute positioning to position the images in the four corners.
This method works fine in Firefox and IE7, but can be very difficult to layout correctly for IE6.
There is another method out there that uses CSS only to produce rounded corners. It does involve a bit of CSS coding, but it does not use background images and will allow the container to be re sized without ruining the layout.
You might try googling "CSS rounded corners"