OK - so now it starts getting a little complicated, so bear with me
The FST is the Figure Setup Tool, the CCT is the Character Creation Tool, which is the latest method. They both have the same end result - the character is rigged. CCT is a lot easier and simpler to use, but I’m not all that sure that it can be used for creating cr2.
You can’t rig in Hex - it is purely a modelling app, but you can use Hex to make the groups used with FST and CCT, but it would be better to use the grouping tools in Studio (just to get the terminology right - Daz is the name of the company and Studio is the name of the app), but there again, I’m not sure you can use those tools to make groups for a cr2.
This is why I asked for Patience to help us out here - she is a big Studio user!
The .obj file does not, of itself, have rigging; that is contained in the cr2 file, which references the .obj file and the texture file to make a complete character. So, when you import an .obj then export it back into Studio, it won’t have rigging - it hasn’t been destroyed, because it never had it in the first place!
What you need to do to preserve rigging is to use the Studio-Hexagon bridge. Load your figure in Studio, make sure it is at the base level of mesh resolution - you find this in the Parameters tab. With the figure selected, select File ->Send to Hexagon. That opens Hex, with the figure in it.
You now do the mesh changes as explained - making sure not to add or delete any verts. For this way of doing it, do not delete the textures.
If you need to close down and get some sleep, what you do is save the Hex and Studio files. Next day, open the Studio file, send to Hex. Close that Hex file and open the one you saved and continue.
When you’re done, in Hex’s file menu, hit Send to Daz Studio. Studio will have been minimised - click the minimised button to open it and you’ll get a menu asking whether you want to save as a morph. Give it a unique name and accept.
Your morphed character will appear, all rigged and textured. There will be a morph slider under the Parameters menu, under Morphs-> Hexagon Bridge. Slide that to 0% before saving. Now comes another tricky part - saving your new morph. Prior to the latest version of Studio, this was simple - you saved it as a morph. There was a discussion recently that there was a problem with the newest version, but this was never resolved. I’ve just done a quick trial by saving a Studio scene and the morph wasn’t saved in a Studio scene file.
Better you get some expert advice on this before proceeding - maybe over at the Studio forum - you can refer to this discussion to put it in context. Your work won’t be lost, however - you’ll still have the Hex file to use once this issue has been resolved - to either save the morph or to make a new character.
The alternative is to make a new character. This process is pretty involved and needs a complete tut all on it’s own - of which there are plenty on the Daz site. I can do a brief explanation, but will leave that for now. The morph process will serve you better, so rather get some clarity on that before proceeding
If you do get clarity, please come back and let us know - I’m sure many folk would be interested.