One thing to try, but I'm not 100% sure on this since I really don't do modelling would be to try exporting your rigged figure from blender using COLLADA instead of wavefront .obj.  I believe collada will export rigging information, but I don't really know how successful that will be when trying to import into daz studio.  According to daz, the collada import in studio has been much improved with the 4.5 versions.  The worst case will be that you will have to re-do the rigging using the tools in studio at least the 4.5 pro version is still free and gives you access to all the advanced tools like rigging.

I hope you can find a solution that works for you, best of luck and I will be interested to see your end result in studio.