Plot multiple lines/tracks/routes in single kml-file

Hi all, I am trying to plot multiple lines/tracks/routes with multiple gps-points into a single kml-file, where the routes should not connect themself with each other. Basically I use

kmlwriteline(filename),gpsb,gpsl,'Color','blue','Width',3);

to write a single line into a single kml-file.

Is there a way to plot multiple lines into a single kml-file or to merge multiple kml-files into a single one?