That's where I started. I made an obj file and tried C4d's textures, and tried modifying them to suit. The outcome looked nothing like what i'd made in Stager with Substance materials, however hard I tried.
So recreating all the characteristics of the material hasn't worked yet.
I might try to recreate it, copying every number of every attribute in each material, but it'd be hours of work and no assurance that it would look similar, since I don't know that the numbers mean the same in both systems. I'm not sure what the built-in materials support, and the Redshift materials system is way too convoluted for such experiments, since I can't make anything in that system without watching oodles of video tutorials. Can't find any written, searchable help material that describes how to make things, the Maxon help files just describe each element, and in short, jargony text.
So I think I'll give up, unless I find some way to convert the materials.