If a half elf or bard takes riposte strike:
At-Will Martial, Weapon
Requirement: You must be wielding a light blade.
Target: One creature
Attack: Dexterity vs. AC
Hit: 1[W] + Dexterity modifier damage. If the target attacks you before the start of your next turn and it is within reach, you can make a Strength vs. AC attack against it as an immediate interrupt. On a hit, the target takes 1[W] + Strength modifier damage.
And a feat which modifies a power's attack rolls such as Adept Dilettante:
Benefit: You can use your Constitution, Wisdom, or Charisma modifier to determine bonuses to attack rolls and damage rolls with the power you chose for your Dilettante racial trait instead of the ability modifier that power normally uses.
or Combat Virtuoso:
Benefit: When you use any attack power gained through a multiclass feat, paragon multiclassing, or the half-elf ’s Dilettante racial feature, you can use Charisma for the power’s attack rolls rather than the ability score normally used to make the attack. You still determine damage normally.
Is the secondary attack's primary stat changed?