Strip @domain.com before auth.

Hi, Currently, I am accepting users with and without a realm name. I am satisfied with the acceptance of users without a realm name, but not with users that do have the realm name. I do have set up in my proxy.conf to accept the realm as so: realm domainexample.com { type = radius authhost = LOCAL accthost = LOCAL } This lets me authenticate against the same user base as users that dont include the @domain.com in their user name. My problem is this. I would to strip the @domain from the username before the authentication takes place? how and where is this done? Thank you in advance.