You can send a model from ZBrush directly to Poser without it coming from Poser first, just need Poser to be the active app in Zbrush's GoZ menu. It won't have groups (tho Poser will read ZBrush polygroups and assign random numbers to the group names, which you can change via the grouping tool if you want).

Normals require UV maps first, which he said it doesn't have, but that would be the more appropriate way of handling this.