Copy Controller copies the highlighted item to the clipboard.

(Copy)Ctrl+CYou can use Copy and Paste to copy object and modifier tracks, controllers, objects, and components, depending on what you are working on.

Not all tracks can be copied and pasted. The rules for using Copy and Paste in Track View are:
To copy and paste a modifier in the Track View Hierarchy:
Highlight a modifier track.
Press Ctrl + C, or from the Edit menu, choose Copy.
Click the object track for an object in the Track View Hierarchy.
Press Ctrl + V, or from the Edit menu, choose Paste.
The Paste dialog opens.
Set the options in the Paste dialog, and click OK.
The pasted modifier is inserted above the object track you selected. It does not replace any of the tracks in the target object.
To copy and paste a controller in the Track View Hierarchy:
Highlight a controller track.
Press Ctrl + C or on the Track View Edit menu, click Copy.
Highlight the controller track for an object in the Track View Hierarchy.
Make sure you choose the same type of transform that you copied.
Press Ctrl + V or from the Edit menu, choose Paste.
The Paste dialog opens.
Set the Paste options and click OK.
The controller is pasted onto the selected object.
To copy a controller in the Motion Panel List Controller Rollout: