I don't see that file format listed as a compatible format for any of the magix products, or in fact any of the other products in this price range. I think you need to find a file converter (and that is going to be difficult) to convert those files into something more current. I say difficult, but likely not impossible. I just don't have the time to go out and research this any more than I already have. Sorry.
I believe that Samplitude MX can import many types of audio files. I may be wrong. You can add CD's, WAV files, or MP3 files.You can also "drag and drop" any audio file on your hard drive. You can also drag any audio file directly from "Windows Explorer". the MX stands for "Media Exchange".