You can export in c4d format, but as you mentionned, only for R5, wich is not useful. 
Exporting entire scenes is only possible in 3ds and lws formats. So you should try 3ds. Bear in mind that ecosystems won't export ( thousands of instances to export isn't possible), and that Vue procedural materials will be translated into bitmaps , so they may not look exactly the same, and sometimes, they will even look very different, as thundering1 already mentionned.