Here's an example of an INCLUDE statement to keep only records where the 3-byte PD value starting at position 21 is greater than or equal to +125:
If you need more specific help, you'll have to give more details of what you're trying to do.
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: