Merge files from seperate roles.. (MS Project)

[guange]

Hi, I'm work in software house in Thailand. In here, we seperate all of work into a role (like programming, testing) and Head role will plan the Resource usage for his role. The problem is I want to merge the resourge usage that's come from each Head role into 1 file (group by task). How can I do??

Now I try to use Insert->project but it's can't group by task.

Thanks for Help..

Have a nice day..