Yes it is! Though it will require some coding. There are two different APIs that are used for this, the link below describes the first, and most commonly used. (For Windows 7)
For Pro audio or controlling another device (such an external USB) you would want to use the Endpoint Volume API (I have given you a link here directly to that code sample with instructions on getting it up and running in the SDK.
And the last link here has C++ code to do it to AGC. Be sure to scroll down for the complete solution in the second code block :)