I went back and read your original post. Actually, there are probably several answers to your original question with lactose being one potential answer. "A little sweeter" is pretty subjective so you're going to have to exbeeerinment a little to find what tastes right to you. I make a brown that I use 6 oz. of lactose in a 5 gallon batch to "just take the edge off" for me. That may be too much or too little for your beer taste. I don't know if you could add some to your finished beer to taste and back calculate like we do with things like bourbon or not. It may just have to be trial and error. I add it with about 20 to go in the boil (just ahead of my IC) because it clumps up like DME and you need a little time to get it dissolved. Lots of info on the web about using it in beer too.
Good luck and happy brewing!