You could make a script on the ring so that when it's on, an activator (something small, like a diamond) will move to you and cast a ranged spell. Example:
Scriptname TEST extends ObjectReference
Property ObjectReference TheDiamond Auto
Property ObjectReference YourRing Auto
If Game.GetPlayer() .IsEquipped(YourRing) == True
TheDiamond.Moveto(Game.GetPlayer())
Wait(.1)
TehSpell.Cast(TheDiamond, Player)
Endif
If Game.GetPlayer() .IsEquipped(YourRing) == False
Game.GetPlayer() .Dispel(TehSpell)
Endif
Try that. Don't forget to define the properties, too.