Casting spells on MA target

[muffinnn21]

Hi,

I'm wondering if this is possible with the current tools we have with WoW.

The goal :
While targetting a friendly unit and trying to cast a harmfull spell, the addon would check if the target of my target is a valid target for my spell and if so, it would cast the spell on it. There's an addon that cast spells on yourself if it cannot be cast on your target(bandage, heals, shields, etc) and I wonder if this kind of assist addon can be done.

tkx