I assure you, there are none.
You can only cure yourself, which is useful when soloing.
I could add it but then I would have to add code that checks on every target and implied target change whether the target/implied target is one of your group members, and then enable the appropriate icons for it. That would eat up a bit of performance.
I'm quite sure that you are the first person ever to request this also. I think that most healers will rather have their eyes on the group window anyway and cure from there. The whole point is that you can cure people without changing your target.