PhilC's Obj2Cr2 is designed to take an obj file and create a cr2 for it. This add on does not create weight mapped rigs. The biggest problem you will have is that you will have to take the clothing obj into your modeller and fit it to your figure. You don't have to group it or do anything other than fit it to the figure. Save it and import it into Poser. Open up Obj2Cr2. You will have to determine the best template to use to for the cr2. If the figure you are using is supported by the plug in (even if it is heavily morphed, use that template. If not, go for the closest one. Follow the steps for the plug in. It can take some time for the cr2 to be created so be prepared to wait a bit.

What figures do you want to use? PhilC's WW add on support is pretty extensive. Between versions 1 and 2 (I purchased them long before SMS added them), there are few figures I don't have support for. Check through the various WW2 figure support packs (the large ones with multi-figure support), you might find the figure you are looking for in one of those. I also have a couple of figures that Phil included WW support for the figure (the Troglodytes were one) with the package.