The LD editor fully supports drag and drop for moving or copying objects. To move objects, select them and simply drag them to the wished position, in the same rung or in another rung.
To copy objects, you may do the same, and just press the CONTROL key while dragging. It is also possible to drag pieces of diagrams from a program to another if both are open and visible on the screen.
At any moment while dragging objects you can press ESCAPE to cancel the operation.
Alternatively, you can use classical Copy / Cut / Paste commands from the Edit menu. Paste is performed at the current position.
You can manipulate whole rungs by selecting only their head in the left margin (select only the cell where the rung number is displayed).