The simplest solution to generate XML file from Fusion CSV report output

Summary:

What is the simplest solution to generate XML output, in a required XSD schema, from CSV Fusion Apps report outputs?

Content (required):

The SAF-T legal report is needed, in many EU countries, in a specific XML format. Fusion Applications currently generates a ZIP containing the required information in more CSV files. This is done through a Java program, called from ESS ui.

What should be the best approach to extend Fusion in getting these files and formatting them in a specific XML output, as per technical requirements each country has? With current PaaS products Oracle has, there could be many options. But want do you recommend, as being the simplest and with the lowest costs?