By ADM(V8), do you mean ADM1 as opposed to ADM2?
The application I'm working with is ADM1-only (even in current Progress versions), and I haven't heard about SDO. Judging from the ProKB SDO is an ADM2 thing.
When you post what you are trying to achieve I could try to tell what I would do.
If you are actually working with Progress 8.x things may be different, but it should have the basic ADM1 constructs.