Reference Project

Hi,

I try to create a specific reference to projects that takes into account the project code and not the parent project.
Currently I have created a field in the database table name reference project and I added this name in the Master File model / Project.php. He created good reference but if I specify a project code and no parent project it does not put me in code project.
Can you tell me the mache to follow to do this?

In the same idea I have to create refenreces specific documents. Where can I format the code?

Thank you for your help.

Ok, sorry.
So in project1.png, I create a project where you can see refenrence realize. It hasn't project code I insert in the case associate. I want to generate this reference with project code.