I've been trying to find a way to do this forever and I recently saw a script on a macro someone else was using that made me realize how.
First, you'll have to goto "create custom macro" within clique.
then, here's my example:
/cast Righteous Defense
/run local n = UnitIsPlayer("mouseover") and UnitName("mouseover") if n then SendChatMessage("Taunting up to 3 targets off you!","WHISPER",nil,n) end
this same script can be used to whisper the target of any spell you cast using clique (because anybody you're casting a spell on is your mouseover target) just be sure to change the "Taunting up to 3 targets off you!" part to whatever your message should say.