You can use the tovoicemail.pl script that is included in the /usr/local/fop2 directory. However, the script will probably NOT work untouched, you will need to verify path/directories. Look at the comments at the top of the script to see what is the recording filename that you must use to make the script work. Also, the script does a mix of in/out legs into left/right channels, making a stereo file unsuitable to be played back by asterisk, but that works well with the voicemail explorer in fop2. If you want to listen from the phone, you will have to tweak the script so it does not pan the legs of the call in stereo.