After Effect: AE script to replace text in text layers from a csv file

Current : I have a project I set up for a client that needs to be easily customizable for each of their series. It has a ton of text layers which will each need to text replaced. I figured it would be easiest to offload this to an easily editable text file and automate the customization process. I got it working using an expression, but since the project will be handed around a lot, and expressions don't handle relative file paths, I'm thinking a script will work better. Expected Scenario: 1) Run the script 2) Select an external csv file 3) Replace the text in specific layers in the project based on data in the file