XML to Text Conversion

I need a software that will convert a valid XML document into text. It must be flexible enough for me to specify which elements to convert and of what format. The format would be to write the elements’ data (excluding the element name), specify the number of characters for each elements’ data, and specify where there will be a space or new line. If you know such a software, or even something close to it please tell me. Thank you and have a nice day.