To be honest the most easiest way would be to reverse engineer the xml and write the properties in the given structure - the XML is pretty trivial: a root element with a child for each sample that has certain properties. multimic samplemaps have one child per sample containing the filename of the file position. The properties should all be self explanatory, but if something's unclear I am happy to help out.
You can use the JUCE ValueTree and its createXML method, this is how I create them myself.
