With Filestar you can easily convert RM to SND. Accessible directly in your right click menu for single or batch RM processing. How to convert RM to SND:
1. Download and install the latest version of Filestar. (https://filestar.com)
2. Right click on one or more RM file(s) on your desktop and select Convert with Filestar.
Type "convert snd" in the search box.
3. Press Run.