There should be no re-scaling. So that is Exporting / Importing settings. It's always best to import the figures .obj from it's Geometries folder to your modeling app of choice. The figure is then at Zero pose.

Carrar rigging is not the same as DS/Poser. You can't do it in Carrara. You can do Carrara rigging but that does not transfer right to the other two.

What you can do. Hack the figures Cr2 to point to your clothing .obj. This will give yoiu a conforming clothing figure as long as your clothing has the same grouping and group names.. BUT, you can't distribute it to anyone else. It is only for your own use. Very important to remember.

eg. using the V4 figure Cr2. There are 2 lines in the Cr2 that needs tp be changed.

1. Open the V4 Cr2 using WordPad or any Cr2 editor free in the freebie sections here.
2. At the top of the file you will find the first line you need to change.
       figureRezFile :Runtime:Geometries:DAZPeople:blMilWom_v4b.obj
                                     Change to point to your clothing .obj
      figurerezFile :Runtime:Geometries:(what ever file name you have it in):(whatever name used).obj
3. Scroll down a bit and you will find the second line to change. it's the same as the first.
4. Save as a new name. you don't want to overwrite your original Cr2.

You now have a working Cr2 for your clothing item.

Other wise you will need Poser or the DS setup tools, sold at Daz, which are not cheep.