You must delete everything from the CCF exept the panel or device you want to copy.
I would save this file
Then open your CCF and merge.
it is better to replace, then open the file saved and merge
Then use Ctrl and arrow to take the new panel where you want it. save new config as your CCF. PE doesn't allow you to copy and paste from one CCf to another unless you merge the two.
Your way will work, but it will end up getting the system properties of the unwanted file and not the ones from your file