The only way to produce version 7 (.pm7) of Adobe PageMaker from version 5 files (.pm5) would be to use any version of the program above 7 and simply re-save the files. No other way how to do it, as the support for PageMaker formats in other programs is pretty limited, or rather nonexistent.
Convert Adobe PageMaker 5 document file to Adobe PageMaker 7 document.
We found 2 software records in the database related to .pm5 to .pm7 file format conversion.
Microsoft Windows software - convert pm5 to pm7 on Windows
One of the first desktop publishing programs on market
Convert from pm5 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 pm5 to pm7. 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 pm5 to pm7 on OS X
Mac version of once popular publishing program