XML : How I can export an XML file in R?

I want to export a XML file and then open it with AnyLogic (the extension of AnyLogic is alp (also xml)). However, the XML file (simulation model) is static, changing only a few parameters. How could export the file to XML format? I have seen many ways to do it but I have not yet succeeded. In my case it would be more simple to export a string variable that contains all the XML (because the file varies little). For example, if I have a variable MyData = '..........' as I get the contents of that variable is written to a file in XML format? Thank you.