To diaplay non unique username

[DineshSharma]

Hi,

We have a website where we are integrating forums into our site thing is user registers on third party site and we get user id, email , pwd, first name and last name. No Registration or login takes place on our site.

We are able to integrate using unique user ID as username so forum flow doesn't gets affected, but then the ID is getting displayed as display name. Can we make the non-unique firstname & lastname as display instead of the user ID

If yes how to and where to store firstname and lastname.