Create Script on Google Sheet to import automatically a CSV and organise the data

Please read carrefully the scope of the project and only apply if you have understood and if you know how do it. You can also contact me if you need more information. Overview: Create a script by using Google Script Editor to do the following tasks: - Extract a CSV file from an email attachement (I've found a script on Internet so if you struggle with that I can send the script) - Import on a Google Sheet only the needed colums (can be identified by columns headers) but please note that the columns position can change. For example: on a CSV file the column "name" can be into the column A and in the next CSV the column "name" can be in the column B. So the script has to identify the column headers to make sure we have the needed data. - Every new CSV imports should add content to the existing Sheet (not replace) Please apply ONLY if you know how to do it.