Adobe Premiere Pro projects (*.prproj files) can be exported to many video formats, including Windows Media Format. So that is your best, and probably one way how to convert PRPROJ files to WMV format.
Convert Adobe Premiere Pro project to Windows Media Video.
We found 2 software records in the database related to .prproj to .wmv file format conversion.
Microsoft Windows software - convert prproj to wmv on Windows
A timeline-based video editing software from Adobe
Convert from prproj 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 prproj to wmv. 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.
Apple macOS / Mac OS X software - convert prproj to wmv on OS X
Mac version of Adobe's prime video editing software