how to burn dvd from rm video files

i got this Nero 6 software with the purchase of a Sony DVD burner, i tried to burn rm format anime to DVD, but Nero won't allow me to add the files, says can not insert the file
the software burns the dvd is called NeroVision Express 3 i think, is there anyway to burn rm to dvd with nero 6?
thanks

(the other thread said to download an audio plugin for nero, i did that, but still cant add rm video files to the dvd.....)