Since you haven't given any real details about what your PIC X(16) numbers look like, I'll just assume they are ZD values. In that case, you would use DFSORT control statements something like this where p is the starting position of the field:
If you need more specific help, give more details including an example of the your input records and what you expect for output, the starting position, length and format of the input fields, the RECFM and LRECL of the input file, etc.
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:http://www.ibm.com/support/docview.wss? ... g3T7000080