The simplest way... is to use Objaction Scaler and use 96% each way.

That is Enlarge by 96% out of Poser... for use in Carrara... and then Reduce by 96% from Carrara back into Poser.

I have used Objaction Scaler for several years now between Poser/Carrara... it has never let me down and the scaling between the 2 programs is precise/exact.

"You don't have to be mad to use Poser... but it helps"