How to read an OBJ file outside of unity,How do i read an OBJ file outside of unity?

I want to convert an OBJ file located in Application.persistantDataPath to a mesh, but do not know how to do so. I am familiar with converting .txt files into strings or even numbers but can't find anything about mesh's.,I want to give players the ability to add custom hats and to do this I would need to read an OBJ file. The OBJ file would be at the Application.persistantDataPath and i just want to convert it to mesh. How would I do this?