Where do you define your File in the script?

I'm very new to vb and just need to add a static header to my text file, but I don't see where your file is defined.

For instance, I need to add the header 'EXTSYS1|MXOPERLOCInterface|AddChange|EN' to my 'locations.txt' file that I created in my SSIS package.

Thanks!

Emilly