Occasionally I might hang a rope light from the awning roller tube but most times I don't bother as the awning can't be rolled up with the lights still in place. If I cared enough I'd probably do what most others would do these days by installing a self stick LED light strip to the body of the trailer just under where the awning attaches to the trailer, therefore allowing the awning to be rolled up at any time.
I've owned both manual and power awnings and the fact you say you can't reach the power awning roller tube in order to hang lights suggests to me this awning offers little or no tilt ... if so, you'd be better off putting your time & money into modifying the awning so it does tilt, otherwise it will be essentially useless to you. That's why when we bought a trailer a few years ago with a power awning that wouldn't tilt and couldn't be modified so it could tilt I had the dealer replace it with a good ol' Dometic 8500 manual awning that would. Power awning design has improved considerably in the intervening years and we now own another trailer with a power awning that does tilt so rain water can't collect on it and cause it to sag as otherwise would be the case.