Then create a process that reads that file and generates the necessary jcl and control statements to create 'n' members. The generated jcl and control statements would be written to the internal reader and executed. If you wanted to retain a copy of the generated jcl, write it to a file, then copy that file to the internal reader. Which ever of these methods you use, you will need to start the output with a proper JOB statement.
We will help you learn how to do "things" but we won't write them for you.
Hope this helps,