Altering a package variable within R


I'm thinking of making a package (not a cran one but a github come on enjoy no promises it's awesome. One function I have is a plot to dropbox function and retrieve the url.

I'd like people to be able to download the package and then run a function that makes a data set within the package that stores the person's path to their dropbox and their account number. They'd have to input this info one time and it would load after that.

Is there a way to permanently alter a package on a local machine from within R? It seems pretty doable since a package is just a text file.