I want to create a smart collection that contains all virtual copies that I've created. Is there any way to do this in lightroom.
You only need one rule:
File Name / Type →
Copy Name =
Copy Name solution will work in some cases but since you can technically add / remove
Copy Name metadata for any file type (whether it's a Virtual Copy or not) this isn't a fool proof method. Neither is anything else that relies on user changeable metadata fields. Adobe needs to add something to the rules specifically for virtual copies to make this work accurately.