Hello Graham,
Unfortunately currently there is no way to control the position of the DragCue programmatically. We have seen similar requests before and your feedback gives this a higher priority.
Currently if you assign a visual to the DragCue, its RenderTransform can be set to for example a TranslateTransfrom that will allow you to move the visual around relative to its current position. Unfortunately calculating the position relative to your drop spot and updating it may be a bit cumbersome.
All the best,
Miroslav
the Telerik team