I think you can do it. Lucy hardly ever howls. when she's outside and she starts barking I bring her in immeadiately. She learned quickly! (she also learned that if she wants in she can bark at the door!)
I understand what you mean when you say she knows when she's in trouble. When Lucy does something bad and I walk into the room, she puts her head down, walks slowly over to me, and rolls over. A good ploy too, VERY hard to stay mad unless she did something REALLY wrong (like eating me shoes!).
I'm assuming your beagle is like mine - very treat oriented? If so, you can quickly teach all kinds of behavior. Use them to your advantage!
A comment on the running when called - don't call her to you to end a play time - go get her. Lucy only gets called for treats or to retrieve the ball from her so we can play fetch. As a result, she is fairly good with her recall. If we need to go, I lure her over to me in various other ways, but never with a "come" command. Basically, to repeat my trainer, never call a dog when something the dog will percieve as unpleasent will happen immeadiately after. (you may already know all this!)
Bottom line, I think you can teach your pup to stop howling on command. Just be consisent and remember that it is part of her breed, so she can't help that she starts barking!
