Finder window has list of items. One item selected. What action clicks on the item to allow pasting to change the item text?
Typically in Finder, when you have a single item selected, you can hit the return key 
to rename said item. Therefore, you could use the Type a Keystroke action to facilitate renaming.
However, there is likely a better way to do this. What is your current workflow? What are you trying to accomplish? If you can share more information, perhaps we can find a more streamlined solution.