COBOL RETURN-CODE in RPGLE

 >> (Similarly, in C your functions usually take parameters, but also can
return a value which the calling function can capture, and that is done all
the time, which is why I'm baffled that I can't find how to do this between
RPG and COBOL on the 400.)

You can do exactly the same thing with RPG and COBOL as with C.  RPG uses
RETURN varname and COBOL which uses PROCEDURE DIVISION USING ..... RETURNING
varname.

However, that doesn't help if you have COBOL programs using the RETURN-CODE
option.  This is very COBOL specific and has nothing to do with normal
function return values.  The answer you've been given for wrapping it in a
CL call is the only option IF you cannot touch the COBOL code.

I've never known anyone ever use this thing in COBOL let alone try to do it
from RPG!

In future I would suggest you take this kind of request to the COBOL list
where the IBM COBOL developers hang out

Jon Paris
Partner400