Hi,
Inserting projects will certainly work, but maintaining 50 projects linked
to a master without damaging a link and so corrupting one or more files will
be difficult. I would either write a macro to read data and update an Excel
report, or have a macro to automatically create a consolidated project by
inserting projects with NO link. That way all tasks are copied, snapshot
created and assignments for resources merged. You can then filter for
milestones.
A few mods to the macro would add extra reporting.
Alternatively you can have a macro read milestones in Project then export to
Excel.
With Project Server, of course, this is just a matter of adding a View to
Project Web Access and you will get what you need automatically!