How to enable the Endpoints by programming in Vista/Win7

I want to enable a Endpoints by programming in Vista/Win7 which has be disabled, For Example, I have three capture device, “Rear Input”, “Stereo Mix” and “Microphone”, It is disabled in normal of the “Stereo Mix”.
The best way is that it is a document method, Any ideas will be thankful.
Of course I can enable it by manual. I want to do it by programming,I know that we can modify the value of the devicestate key, But it does’nt a document methd.

Allen