Thanks for the reply!
Looks like I'll have to get syntheyes instead. My motion capture program exports:
3ds max (.ms)
blender python (.py) (different from poser python script)
lightwave (.lws)
maya script (.ma)
softimage xsi (.xsi)
text file (.txt)
Daz mention mention that Carrara can use Syntheyes files (most likely .syncar ones which Syntheyes could export for Carrara anyway) and Matchmover pro, (not sure which of the file extensions that it exports Carrara will read).
Still don't know if the camera movement  from Carrara can be exported back into Poser, it could be possible via Poser scene but then I think that some people have been having problems with camera and lights.

Daz Studio 4.8 and 4.9beta, Blender 2.78, Sketchup, Poser Pro 2014 Game Dev SR5 on Windows 8 Pro x64. Poser Display Units are inches