I don't use GoZ for Poser, but rather colorcurvature's PML; however, the basic principle should be the same. Import morphed V4 into Zbrush, press the clone button for the Tool. Import the dress into Zbrush. Clone it as well. Load V4 from the tool pallet. Append Subtool and select the dress. Now the dress is on the figure. Make your changes to the dress. Hide the figure subtool and maybe you can GoZ the altered dress back into Poser.

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