It sounds like you want to refer to files that are in a known location with respect to the source code. So, for instance, I might have a file called "email-processor.rkt" with a file called "email-rules.csv" that's in the same directory. In this case, I would echo Ryan Culpepper's suggestion that you use the runtime-path functions. here's a snippet of code that illustrates what I mean:
#lang racket
(require racket/runtime-path)
(define-runtime-path here ".")
(file->string (build-path here "email-rules.csv"))