nevermore

Hey all, i was wondering if anyone could give me a push in the right direction on how to do this or if it has been dont to send me there code so i could modify it for my needs. I am working on a new site and all the members have e-mail account already but this is by me setting them up trow cpanel i want to know if there is another way i could just script it so when they join it would also make there e-mail account.