C# Data Extraction from Excel to XML

We need parsing code to be written in C# that will perform a transformation between an Excel (XLS) input file that contains multiple purchase orders that need data extraction to a specified XML output format. We will provide the input file and schema for the output file for the transformation process, and you must provide the final C# code and your output results. You may not use the Microsoft interop libraries or any other library that has licensing restrictions associated with it. Freeware and open source libraries are acceptable. We have hundreds of other different types of input files that will need to be processed once we build a relationship with a strong developer.