That's an easy one.
Create the address book group you want to use as storage. (Let's call it Target)
Now create a filter
(As I don't use any replied filters myself, I'd place it there.)
Condition: Address groups - Target - do not contain - sender
Actions: Add addresses from From: to groups "Target"
At the Options tab you need to enable 'This filter is active' and 'Use this filter for manual re-filtering only'
Next thing you select the folder you want to process and you pick from the menu:
Folder -> Re-filter -> select 'replied messages' and 'manual filters only' -> OK
Now you're done
I'm just a user of The Bat! I don't work for Ritlabs.