According to the RAD-EAD Matrix developed by the Canada Council on Archives, the proper way to encode the provenance access point is through the <origination> element:
The Archivists’ Toolkit (AT) creates an <origination> tag from the name link, specifically the name(s) where the link function is “creator”:
So, all I would need to do to create a RAD access point would be to use the “role” attribute in the name element and indicate “provenance.” The AT has a long list of roles, but “provenance” is not one of them. And the program does not allow the list that these terms are pulled from to be edited. You can pull the “Name link creator / subject role” list from the Lookup Lists, but you can’t add items or edit items:
I’ve posted a query to ATUG-L, and will post an update if we find a solution.