VPJ projects are usually created with some video editing tool, like VideoPad or similar (same extension, different format). This conversion basically represents import of mp3 audio, some editing and saving project in VideoPad or similar. It is not a conversion, rather standard workflow in the program.
Convert Compressed audio and music file, mp3 songs or ringtones to VideoPad video editor project file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert mp3 to vpj on Windows
A video editing software for Windows
Convert from mp3 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.