Using at sign "@" in password Oracle Database/Forms

We have an application running in Oracle Forms which connects to an Oracle database (12c). We've always had issues with using the "@" sign in passwords so we always instructed our users not to use the "@" sign. Is there a way we can use this? Maybe some modification to the formsweb.cfg or something else? We connect to an Oracle Database via Oracle Forms. Many thanks in advance! Best regards, Roël