First go at embeded SQL ... With a subfile.

Well, I've jumped in over my head with this one... I wrote my first
maintenance program using a boilerplate source kindly given to me by Don
Nitke. (Thank you Don!) It actually looks pretty good AFAIAC. 

What I want to do is to be able to change the sort sequences in the
subfile. I think I could do this with multiple logicals, but I want to
know if this is possible with SQL, and therefore not need the logicals.

In starting my conversion, (and I'm just trying to replace the current
logic - additional sorts to come later), I'm beginning to slog through
Roll Forward and Back, getting the specific record I want to edit, and
updating that record. Can anyone point me in a more logical direction
than I am seeing now?

The SQL that I am using just reads forward, like READ. I got to Roll
Back, and got stuck with trying to find out what is the equivalent in
SQL for READP... My first embedded SQL program was just a list. No
problem (when I finally got it finished). But this is looking like a
major project. Any comments on reducing the perceived size of this
monster?

Any suggestions appreciated.

Dave