Melee Training Feat from Heroes of the Fallen Lands, say you can sub another Ability mod for your melee attack bonus and half that Ability mod for damage bonus. PC chooses Dexterity.
Riposte has, If the target attacks you before the start of your next turn, you make your riposte against the target as an immediate interrupt: a Strength vs. AC attack that deals 1[W] + Strength modifier damage.
If PC has both feat and At-will doesn't the interrupting attack now goes as Dexterity vs. AC. Attack deals 1[W] + 1/2 Dexterity mod?