Q: what do i do if I lost the package with the remeed code for the digital copy?

I just realized what it means to have the digital copy of the dvd's I have bought! I keep all of my dvd's in on cd case and have thrown away many of the papers that come in the prepackaged cases. Is there any way to get redeption codes for the digital copy movies I own so I can load them into my itunes account?

Thanks