I agree with @FINET_Laurent that this process can be more complicated than it might seem sometimes, depending on what type of data or object is being copied / pasted, and what the current situation is like. Previous selections need to be cleared, wanted objects need to be selected, then copied, then they need to be unselected, then some navigation is often needed, then some sort of user interface interaction, or change in 'system focus' needs to happen, to indicate where the data/object will be pasted.
But below are a couple tips to help along the way:
ThisApplication.CommandManager.ControlDefinitions.Item("AppCopyCmd").Execute
ThisApplication.CommandManager.ControlDefinitions.Item("AppPasteCmd").Execute
https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.clipboard?view=windowsdesktop-8.0
In an iLogic rule, we can often just directly type in "Clipboard" (without the quotes), then type the dot (.) after it, to see all its properties & methods that are available to us. Using that directly on things other than text though, can be more complicated than using the Inventor commands.
Wesley Crihfield

(Not an Autodesk Employee)