Unfortunately, this is not possible with the standard Lists control that comes with Sitefinity. It sounds like a good idea, so we'll try to see if we can add this as a feature in one of the next releases.
The only way to achieve this now is to create your own Lists control, bind it to the data by taking advantage of the Lists API ( http://www.sitefinity.com/help/developer-manual/lists-api-walkthrough.html
) and then implementing the desired behavior through Java Script.
I am sorry that we are not able to be of more help at this moment. Let us know if there is anything else we can do for you.
the Telerik team