How to copy code from one field to another in Creator?

How to copy code from one field to another in Creator?

Hi, I have attached code to a field using the very useful drag & drop. I would now like to copy the code to several other fields, rather than having to recreate the code every time by drag & drop. Maybe I'm being rather dense, but I can't see how to do this - can anyone please tell me if there is a way to do this?