Hello every one, any one has any idea on how to customize or modify the logic for "print remittance"

Hello every one, any one has any idea on how to customize or modify the logic for "print remittance" program to derive the email id from Customer Account, not from Customer Account Site.

Currently the email id is deriving from Customer Account Site level when we ran "Print Receivable Remittance" Program which is deriving and sending the email based on Customer Account Site contact 

But the requirement is to derive email address only from Customer Account level only against the contacts