Oh, another option I forgot.

You can use the grouping tool in Poser.
Select all groups (except the feet and toe groups) and export as a prop.

You will have a single grouped obj file, only containing the dress, ready for use in the cloth room.

Ach, sometimes Poser can be so flexible in its endless possibilities.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!