Run macro from included subproject?

Hello,

Consider this scenario:

- Create a new mpp file "projectA.mpp"
- Add a macro that will display a message "Hello from Project A" which runs when the file opens (so when you open projectA.mpp you get this message)
- Save and close "projectA.mpp"
- Create another mpp file "projectB.mpp"
- Add "projectA.mpp" as a subproject in "projectB.mpp"
- Save and close "projectB.mpp"

If I open "projectB.mpp" I don't get the "Hello from Project A", even though it is added as a subproject.
How can I run the macro located in "projectA.mpp" when I open "projectB.mpp" ?

I need to get it working in the scenario above, so I cannot add another mpp file that will serve as a masterfile and contains the macro.
ProjectB has to run the macro stored in ProjectA.

Thanks in advance!