@KC86_ME Thanks for reaching out. Assuming that this would be manual work where you update the local CSV file and make changes and the same is uploaded every day at a specific time and uploaded to web API. Please correct if my understanding is right.
The next question would be where do you make changes to the excel file is it using some tool that update the local file in VM or in onedrive and some process copy that files to the VM so it will help to understand what function your exe does and according you need to replicate the same using Azure function.
From the function perspective you can run the exec using C# language, but you should know how the excel file is updated locally as you need to have some automation in the runtime either to get the file stream to the azure function and then process it by your function.