What does $SUPER do?

I am needing to run multiple NONMEM jobs in a simulation study to look at the effects of various kinds of model misspecification. Does $SUPER allow me to set up multiple NONMEM estimation steps that each access different datafiles or different parts of one datafile? Or does $SUPER have some other purpose? ---------------------------------------------------------------------- LEGAL NOTICE Unless expressly stated otherwise, this message is confidential and may be privileged. It is intended for the addressee(s) only. Access to this E-mail by anyone else is unauthorized. If you are not an addressee, any disclosure or copying of the contents of this E-mail or any action taken (or not taken) in reliance on it is unauthorized and may be unlawful. If you are not an addressee, please inform the sender immediately.