This conversion is usually meant as a database conversion from an exported CSV to XML based format. This basically rewrites the syntax from the original CSV and uses a new one in the XML. Generally, simple databases may be converted with spreadsheet programs, whilst complex one require dedicated database software. You usually have to select what symbol is used to separate values as various regions can use different characters.
Sometimes some manual tweaking and editing may be needed and the user needs to polish the resulting file. Sophisticated CSV to XML parsers from programs like Stylus Studio can be of great help here and can save you lots of times you would otherwise need when doing things manually.