If any program is capable of converting .dev files to .devpak, it would be Dev-C++ from which both of these files originate. Whenever this conversion is actually useful or even possible could not be verified from open sources.
Convert Dev-C++ project file to Dev-C++ developer package file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert dev to devpak on Windows
IDE for C/C++ programming language
Convert from dev 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.