If I understand you correctly, this sort of thing can enable a regular rack.
https://salsacycles.com/components/c...acks/rack-lock
I've been very happy with it mated to a topeak rack.
Another approach
https://www.thule.com/en-us/us/bike-...-rack-_-100090 I use this on my front end; I didn't have any eyelets up there. Also works well.