Right Click for Sub-Target on Abilities

The abilities to activate the subtarget with a single click would be really good for multiple targets fights. As a tank there are always situations where I just want to hit a target other than mine with an abilities or WS without losing my auto-attack advantage on the main target, such as a Provoke or a Shield Bash.
Right-Click on the abilities or spells would activate the abilities as a subtarget mode where I can just click on my target and use it immediately without switching targets.Also, it would be useful in defense situation where I would like to Cover a party member.