My concerns is how to mention the remaining fields?
That depends on what you want to do with the remaining fields. Do you want them in the output records after the keys, or do you want to do something else with them? You need to tell us how the output records should look before we can tell you how to code the OUTREC statement to make them look that way.
If you're not familiar with DFSORT and DFSORT's ICETOOL, I'd suggest reading through "z/OS DFSORT: Getting Started". It's an excellent tutorial, with lots of examples, that will show you how to use DFSORT, DFSORT's ICETOOL and DFSORT Symbols. You can access it online, along with all of the other DFSORT books, from: