A .NET application is required to produce an output file (example attached). Information for the output file comes from the input file (example attached), a configuration file (possibly XML but could be something else) and also from data typed into the application window.
The application is likely to have a text box where the Lot No. is typed in, a list box which shows all the files in selected folder/folders and Convert and Cancel buttons.
The user runs the applications, puts a check beside the files they want to convert, enter the Lot No. into the application and clicks the Convert button. The selected input files are processed with the output being saved to a file in a specified folder. The original input file(s) are renamed and moved into a processed files folder.
Please let me know if you require further information.