Be able to add or amend the communication email address for a user

We have a few clients that are set up with either a username or a fake company email address. With the fake email addresses (company logins) they add in a communication email address on the data feed so they receive all comms to a personal email address. There is no facility in the front end to see this field. Could we add in a filed on the users profile in their details area so admins can add and amend this.

We are also finding that if a user comes back to the company and has a different employment number then they are not getting imported as the communication email address already exists albeit on there old archived account. The clients have no facility to change the archived one so the re-joiner can use their original email communication email address.