Taunt callout, complete with target of the target in the shout?

I want to do something kind of silly, but what is the point of Macro’s if you can’t be a little silly!

I want it to cast ‘Hand of Reckoning’ (my pally taunt) on a target.
I have it casting only when there is a valid target,
And then I want my character to yell a line depending on the situation.

If the enemy in question has no target, I want him to yell at the enemy to come here (which I know how to do, ‘/yell %t come here’ works just fine). But if the enemy is targeting someone, I want my character to yell "No [enemy], not [their target], attack me!’

I feel like this can be done in the WoW macros but I don’t know enough to do it with conditionals, can anyone help?

Look into Macro-Talk