Both .pp2 and .cr2 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 prop file to Poser character rigging file.
We have found 3 software records in our database eligible for .pp2 to .cr2 file format conversion.
Microsoft Windows software - convert pp2 to cr2 on Windows
Program for making 3D character arts and animations
Convert from pp2 file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned pp2 to cr2. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A 3D animation software
Apple macOS / Mac OS X software - convert pp2 to cr2 on OS X
A Mac version of the popular modeling tool