I didn't think that was possible since it's based on mpr or vpr
Of your highest non retired toon.
Which is why folk retire.
If we wanted them to stop retiring, we'd have to change this, which would lead to BA purchase/regen cheese shenanigans.
As for targetting retired, I suppose we'd have to somehow stop the retired toons from getting rewards.
Also, there must have been a reason Jon original designed the auto retire system.