I'm sure I can help you, but ATM my internet connection is very slow (storm or other problem). I do not know if my answers are sent

I see that ruffles top edges are not the same. Lower ruffles do not touch belt.

You must use part of dress as a "engine" which move them. If you do not like it make it transparent.

In wings select whole dress object and press ungroup.

In wings create "loop" around belt and "loop cut" deleting upper part of dress. Now you should have skirt and ruffles.

On skirt select loop of polygons on the top (belt) and add them new material.

Export mesh as an obj and import to Poser.

In cloth room edit constrained group => add "new material". Edit soft decoreated group => add ruffles.

I'll try make tutorial with picture within few hours.