Transfer audio from Thunderbolt to PC??

[Daethian]

I want to export some Heytell messages from my phone to my PC. Not all of the messages are mine so I can't use the built in export feature. You can only export your own messages. Heytell says the messages are stored in a database that is not readable expect by Heytell so I can't just transfer them off the SDcard. I was wondering if I could use an audio cable and plug it into my headset jack on the thunderbolt and then into the the PC input jack to get a better recording without the background noise. Anyone know if this will work? I know zip about audio. Does such a cable exist?