Is there a reasonable way to set up a kind of macro within a job stream?
I want to avoid cluttering up the system with command files that are
used in a single job stream.

I have a job stream that builds a list of groups for a new account. Much
of this is pretty simple stuff, so that all I have to change is the job
card for the new account, and set a couple of variables for things such
as group name and volume set. But the NEWGROUP logic is all of a kind,
using !HPACCOUNT, !HPSTREAMEDBY, etc. If I could collapse these
recurring lines to a single macro, it would greatly simplify that part
of the job, shortening it, and I hope reduce the clutter.

The best ideas I can come up with are to build the command file with
echoes as a temp file, or to create a rather large environment variable
that uses the other environment variables, and that seems to me an
inobvious solution.