Hi, Thunder and welcome to Zoom forum.
Sorry it took so long for someone to answer you. Must be the holidays.
Anyway, I'm not a Sonar user, but before I went MIDI/PC recording, I used to record with an MRS802 and exported to PC for mixdown, but I used the free Kristal Audio Engine, which doesn't except any other files but WAVs. This might
also be the case with Sonar. Again, I can't say for sure because I've never used Sonar. There are many who frequent here who do use it. Maybe one or two of them will eventually chime in.
You seem to have all the software you need though (AFM). You might want to try
using WAVs. If, for some reason you only have access to smaller compressed files (such as MP3s) to work with and need a conversion program, may I suggest Audacity. http://audacity.sourceforge.net/download/
. It's a free program and it's got many uses. For MP3 conversions you'll also need the Lame file plug in. http://lame.sourceforge.net/download.php
Hope I've helped. If you need more detail or explanation on how to use Audacity, feel free to PM me.