Both the .crp and .db2 databases originate from dBASE albeit probably from different versions. It is likely some dBASE database management software could convert the data from one to another. Or perhaps some dedicated database conversion utilities may be of help here.
Convert dBASE IV encrypted database to dBASE II database.
We found one software available in the database for this conversion.
Microsoft Windows software - convert crp to db2 on Windows
Venerable database management system with long history
Convert from crp 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.