No please do not. Panadol is acetominophen (tylenol) and not safe for birds or ducks. You can give aspirin 325 mg adult aspirin mixed into 8 ounces of water. Or give 1/4 tablet orally in the back of the throat.
Do the legs seem limp as well as not moving them, like they are paralyzed? Is there any resistance if you move his wings? Was he on the ground when you found him?
Oh I am glad to hear that he is moving now. Hopeully, he will recover. I would just treat his wounds, and try to make sure that he gets enough to eat and drink for the next few days.
Just a follow up my duck lost an eye, so i presume it may be another bird. However the other eye will sometimes partial open but for most of the days it will keep it close. Is it blind? Also my duck constantly lays on its head could it be because of the damage on its neck or if it's pain?