How is the analog CD Audio input (on a motherboard) accessed in Windows 7 mixer?

I am looking for a way to utilize the motherboard CD Audio In analog audio input in my VB.Net application in Windows 7. I have a system which needs to use audio connected to that input (not actually CD audio, but from a custom piece of audio hardware inside the PC box). I am porting my old XP application wherein this input was easily accessed via the XP Mixer. In win7, this input does not show up when enumerating the input devices. I've searched the web for weeks and can only find info on reading audio as data from the CD, which does not help. It looks like MS may have removed this input from the mixer in Win7 for DRM reasons, but the hardware still exists on many modern motherboards, including the one I'm using in my systems. Any ideas greatly appreciated!