I messed around with this a little a few years ago, so my recollections are sketchy. If I'm remembering right though, that API lets you added panels to the Illustrator preference dialog. I believe they're just regular ADM dialogs that you 'index' into the preference set, and functionally they act just as if they were stand alone dialogs.
That said, if you're trying to use it to access built-in Illustrator preferences, I don't think that's the way to go -- I'm not even sure it's possible. If you're just trying to get a preference value you can ask for it using the AIPreferencesSuite -- just look up the name in the AIPrefs file. There are no 'secret' prefs in AI, everything is published in there.
If you're trying to get at items in your own dialog, I'm stumped. Because as I said, my understanding was that it was just like a regular dialog. As I said though, it's been a long time since I looked at this.