I add some brown sugar, Worchestershire sauce, black pepper and a few drops of hot sauce. You can experiment and get your own recipe. The ham is already cooked, so you are just getting some smoke flavor in it and heating it all the way through. An hour or two should do. Baste the ham whenever you think it needs it.
Sweet potatoes go good with pineapple ham.
Peel your sweet potatoes and slice into half-inch thick slices. A couple of mini marshmallows might go good in there too. Wrap each potato tightly in heavy-duty foil for the grill. The sweet potatoes will take a while to cook. Turn them on the grill about every fifteen minutes to distribute the heat.