There are a number of ways you can load the Company Name and other fields into the property set for use in the Delphi build action. The PropertySet assign properties action allows the setting of the fields directly as you require. Another option is to load the PropertySet values from an ini file, or an assemblyinfo file. This allows you to have separate settings per project if you require. Simply have a separate ini file per project with the relevant property set values as you require.
I thing th good to do is to read the project settings (like you do when the dpr file is used) and geek the version information and only override the field that is pecified in the setting panel.
Is this a better solution than maintaining another set of (in our case) 100 project file ?