Just saying "an XML file" isn't really enough information, you need to know more about the "schema" (specification) of the XML file. An XML file can hold anything as long as it follows some general XML language rules, but a program like that requires the XML file to have a specific design and contain specific things.
An analogy ... it's like saying "speak English", when the requirement is for a specific type of language e.g. you're giving a speech to a group of car salesmen. You need to know exactly what type of XML the program needs. If you give me the name of the program, I may be able to find out more.
But you may be going about this the hard way. Does the program have an "import" function somewhere? That might be more flexible, and accept text files etc.