Both .cr2 and .pp2 files originate from Poser 3D modeling software and are probably supported in other modeling programs as well. However it is not clear whenever you can actually convert one to another, or if you just export some parts of it. If you need help with Poser files, consulting forums about this program is probably best advice we can give you.
Convert Poser character rigging file to Poser prop file.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert cr2 to pp2 on Windows
Program for making 3D character arts and animations
Convert from cr2 file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.