I have this idea of implementing a software for you project. I am sharing my idea here, please let me know if this works for you or not. (I will made software in JAVA language, on which I have 8 years experience.)
Software will read the CSV and upload the products into the Amazon account using Amazon Web Services. Software will be configured like this -- It should have some map of file name pattern to the fields position. It is a mapping of header names in different language to english. So based on these mappings Software will map the CSV fields to the Amazon webservice request and invokes the respective Inventory API.
This mapping/configuration file is just a simple xml, which can be editable easily.
For these I need the following to start work :
1. You need to sign in for the Amazon developer account and provide the details.
2. If possible can you provide english list instead of spanish, so that I can make a sample mapping file easily and can test it with the software. After I can generate the mapping for spanish and will test it once the software is successful with engish
Please share you thoughts and any issues with this implementation.