Recording to computer while listening from receiver+speakers?

[AwArEnEsS]

While I am listening to the radio(on internet) broadcasting,I want to record the broadcasting as files on computer.Receiver is connected via Digital Optical Out to the computer.The problem is,when the audio setting on computer is set as "Realtek Digital Output",I am not able to record the audio on computer to files via a sound recorder program.But if I change the setting and set the setting to "Realtek High Definition Audio" which is analog output,then I am able record audio on computer to files without problem.But of course the receiver doesn't respond when I do this.

The recording device is set as "Stereo Mixer".

Is there a solution to this problem other than connecting the receiver to the computer via analog cables?