I guess no one wanted to put out an answer for you on this one. As far as I know, Express Animate uses a specific memory location for CUTTING, COPYING, and PASTING. So when you do any of those actions it looks at that memory location and either puts a selected OBJECT in there or takes one out. There is only one of these storage locations within the Express Animate environment. And this is only a local environment and not global within the operating system's environment. So the answer you are looking for is a "NO"!
On a lot of my projects there are many objects that I use on a regular basis. What I do instead of recreating them is to create them all once and have a master project that has all these OBJECTS. So all I do is load the master project in and delete the OBJECTS that I will not be using on the current project. This was the best solution for me in relation to your question. I hope this helps you out a little. Happy Animating.