At this moment there is no way to reference Users list directly. You need to create separate list (as numbered list with text formatted properties) in your model and populate it manually or via import from users list.
Thanks for the feedback. But this does not solved my problem. I need to get the user details for my email body. I agree with you that at this moment no way to reference Users list durectly. Maybe i'll just post this to request for enhancement. Thanks, dennis
You could create a dummy user list and put selective access on this list. You then can create a module that has the dummy user list and one Line item with a rule NAME(ITEM(dummy_user)). This module you then can use as a source for a process to populate a cell in a different module. The selective access will make sure that only the name of the user is being copied.
I have not been able to create a solution based only on formulas, but with a process it works. Hope it works for you.