Hey there! If you judge a target and someone hits the target they are the one that gains the threat for the judged ability. It won't count as your agro unfortunately.
Here are your best options: Consecrate, Thunderclap and Swipe, all based on what kind of tank you are. If you take Emanating Light you can have Consecrate follow you, which really helps quite a lot. There's also all kinds of Thunder enchantments to improve Thunderclap, based on how much you want to spend. Holy Guardian might help you with the 'gaining agro from healing' possibility as well. And swipe is just pure awesome, especially with Anger Management. Mix that with Carnage Incarnate and add a 'bear rend' between your swipes to keep things going.
But here's a better possibility based on what you are talking about: find another way of dealing persistent damage. For example: you could always take Divine Storm and Art of War, using it to blast targets or heal yourself for more agro. Or you could take Corruption and Sinister Strike and finally Pestilence. This lets you spread Corruption to everything within 10 feet of you with a single spell and a single melee strike. Then take Seed of Corruption and Nightfall and start throwing around free explosions of shadow energy. I'm running a tank based on this idea and it is a lot of fun as long as I manage my mana correctly.