I have found out how to set my account to forward all email, but I only want it to forward emails that are coming in as my alias account. When I set up my rule and set it to forward to a particular email address, I receive a confirmation code but I dont know where to put it. 

To be clear, I removed my old forwarding addresses from mail settings > email forwarding so there is nothing there. I go to mail settings > filters and create my rule. I set my rule to forward emails coming in for X and send it to Y. If I click the email address found in the list of rules, it sends me a new code but I dont have anywhere to enter it.