External DS as parm

I want to know if this will work.  I have a main program calling a
subprogram (XCPRIC) that I am prototyping.  The parms are external data
structures.  The prototype (copied in to main program and subprogram) looks
like this:

     D XCPRIC          PR                  ExtPgm('XCPRIC')
     D  pCustDS                            LikeDS(CustDS)
     D  pItemDS                            LikeDS(ItemDS)
     D  pInvDS                             LikeDS(InvDS)

In the calling program(s) I have the following:

      /Include QProtoSrc,XCPRIC

     D XCPRIC          PI
     D  pCustDS                            LikeDS(CustDS)
     D  pItemDS                            LikeDS(ItemDS)
     D  pInvDS                             LikeDS(InvDS)

     D CustDS        E DS                  ExtName(DMCUSMST)
     D ItemDS        E DS                  ExtName(DMITMMST)
     D InvDS         E DS                  ExtName(ININFODS)

And then call it like this:

      XCPRIC(CustDS:ItemDS:InvDS);

In the subprogram XCPRIC I have the following:

      /Include QProtoSrc,XCPRIC

     D XCPRIC          PI
     D  pCustDS                            LikeDS(CustDS)
     D  pItemDS                            LikeDS(ItemDS)
     D  pInvDS                             LikeDS(InvDS)

     D CustDS        E DS                  ExtName(DMCUSMST)
     D ItemDS        E DS                  ExtName(DMITMMST)
     D InvDS         E DS                  ExtName(ININFODS)

      /FREE
      CustDS = pCustDS;
        ItemDS = pItemDS;
        InvDS = pInvDS;

        . . . do whatever . . .

      pCustDS = CustDS;
        pItemDS = ItemDS;
        pInvDS = InvDS;

        Return;
        /END-FREE

Some of the subfields in InvDS are updated.  Will this work?

-- 
Jeff Crosby
Dilgard Frozen Foods, Inc.
P.O. Box 13369
Ft. Wayne, IN 46868-3369
260-422-7531

The opinions expressed are my own and not necessarily the opinion of my
company.  Unless I say so.