Table drag and drop (holding only one column)

I wanted to do draggable table rows, I found TableDnD jQuery plugin and it works fine

$(function() {   $("table").tableDnD(); });

As you can see there: http://jsfiddle.net/drBfS/1/.

But I wanted to make only one column draggable. I mean, whole row (tr) is moved like now, but you can move row only by dragging left column (td.drag), when trying to drag right column it should be no effect. Have you got any idea how it can be done?