Another Reset Password Scenario

Hi..
I am trying to apply a new scenario where the user who forgets her/his password follows these steps:
1. Enters her/his username
2. Enters a secret code (which she/he entered before in registration form)
3. If the user exists & the secret code is correct .. Go to step 3
3. Enters the new password
4. Click "Reset" button

Note: the original password is saved as a hashed one in AspNetUsers table

How can I apply this scenario?