Wood putty to hold awning screws in rotten wood ?

Epoxy some appropriate size pieces of wood into the holes. Like putting tooth picks in a stripped out wood cabinet hole. You would want to get as much rotted wood out as possible. If the damaged area is too large maybe you could make an aluminum plate with tapped holes and screw through it into better wood that is farther away from the damaged area. I like the loctite quick set epoxy.