After effect project Path expression to Premiere pro

Hi,

I need to be able to quickly change my Essential assets language. In that purpose, I've made an expression that read the content of a file and display it. I've then made a little c++ script that allows me to quickly change that file language.

The  probleme is that I NEED to access my text file via relative Path. What I've done in AE, is that I get the after effect project path

projectPath = thisProject.fullPath;

and then i tweek it a bit to get to the folder I need. This works nicely in AE, but as soon as I export the Essential Graphic and use it une Premiere pro, it is no longer able to get the project path.
Even tho both my Premiere pro and After effect projects are in the same folder, along with the Essential Graphics. 

Do I need to access the project path via another code line ? Or  is there at least any other way to use / get a relative path to my .txt ?