I don’t use ZBrush but I’m a Cinema 4D veteran and, some time ago, a ZBrush/3DCoat/Cinema 4D user contacted me to know if I could create a way to make Cinema 4D use the polypaint information that is included in the .OBJ files exported from ZBrush.
So, I created a set of tools to deal with that missing feature in Cinema 4D. But, in the process, I created much more that just a tool to load RGB information from .OBJ files.
I created tools that allow for the loading, saving, creation and editing of true Vertex/poly painting on any editable mesh.
My plugin reads RGB information stored inside .OBJ files saved in zBrush/3DCoat or meshlab format. It also allows to save .OBJ files (in ZBrush format) that include that RGB information. The same for .FBX files (in version 6.x, ASCII format).
But true Vertex/Poly painting can be created from scratch too.
Check out these videos I created while developing the plugins:
https://vimeo.com/98089097
https://vimeo.com/98694731
https://vimeo.com/99060291
And this is the promo video:
I’m getting ready to produce a longer demo movie, showing how all tools works.
So, now there is a better bridge between ZBrush and Cinema 4D. Before, only mesh data was available. Now, even PolyPaint colors can be swapped in and out of Cinema 4D.
Let me know what you guys think 
Rui Batista