Hi,
We have a requirement to drag the label from the RadGridView to the Dockable Panel. It should do copy and paste.
Greatful to you if there you could provide samples which does this.
You can examine our samples for drag and drop manager here - http://demos.telerik.com/Silverlight/#DragAndDrop/FirstLook.
I also have added a sample project that shows drag and drop from GridView to dockable panel using custom cue template. I hope this will help in your case.
If you have any further questions do not hesitate to contact us.