You can't get the entity in the clipboard, but you can get the entity from the .DWG file that's written to the temp folder when entities are copied to the clipboard. The name of the file is stored in the clipboard.
Thank you for immediate advice. I want to make a command that the real processing that I want to perform copies it by _copybase command from a certain drawing and analyzes the expansion data of an element added to a different drawing by the processing that _pasteclip does. Is there any good method? Please advise it. Thanking you in advance.