Double clicking on .mpi file opens mypersonalindex, but not the portfolio/data (Mac) about mypersonalindex HOT 3 OPEN

Can you try this:

http://www.ehow.com/how_6150136_associate-file-extensions-mac-applications.html

That is not the issue. When I click on the .mpi file, it opens 
mypersonalindex.app just fine. Even if I right click on the .mpi file and go to 
"Open With:" and then select mypersonalindex.app it opens mypersonalindex.app 
as well.

The issue is that it does not open the actual .mpi file (the portfolio) along 
with mypersonalindex.app. If I go to File -> Open, then I can obviously select 
the .mpi file and open it, but I would think you would want it to automatically 
open the .mpi file with the application. 

http://doc.qt.nokia.com/qq/qq12-mac-events.html

This will require some code changes and some research into handling Apple 
events.  Linux and Windows are much easier to process command line arguments 
when a file is double clicked.