Custom View Keys
From the Existing Objects palette, you can select objects and press CTRL+SHIFT+C to copy the objects. Then you can select the location into which you want to copy the objects in the main content area, and press CTRL+SHIFT+P to copy the selected objects into the selected folder.
In the main content area of the Custom view, you can press CTRL+SHIFT+X to select objects in a folder. Then select another folder and press CTRL+SHIFT+P to move the selected objects from the first folder to the second folder.