ICETOOL is a utility provided free with DFSORT (has been since 1991). ICETOOL includes thirteen operators that perform sort, copy, statistical, report, selection, and splice operations.
For complete information on DFSORT's ICETOOL, see Chapter 6 "Using ICETOOL" of "z/OS DFSORT Application Programming Guide".
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 all of the DFSORT books online, including the two mentioned above, from: