Hi,
Here's a workaround idea, but not using the hard-wired Drag-and-Drop in Opus...
It may take some work, but using script, you could possibly use the "object-to-cursor" action on the specified object to be dragged. In conjunction with IsMousePressed("Left"), which would simulate a dragged object only moving when the left mouse button is held down, and the GetPosition(), you could set the areas on screen where the object would work. A complex workaround indeed though.
Another idea along those lines could be using an object on an Animation Path, i.e. when the mouse cursor is over the object and IsMousePressed("Left") is held down, the object moves along the path in increments, by using a while loop or ticker condition. Someone with better scripting experience may have a better idea.
Hope this helps, if it can be applicable to what you want to do.