Selecting Stereo Mix Record Line

I'm trying to select Stereo Mix Record Line or Microphone Line without success. Making some modifications at this code, I can change the volume, but I couldn't select the active line.

What am I doing wrong? Thanks in advance.


mixerline.cbStruct = sizeof(MIXERLINE);
mixerline.dwComponentType = MIXERLINE_COMPONENTTYPE_DST_LINE;
result = mixerGetLineInfo((HMIXEROBJ) mixerHandle, &mixerline, MIXER_GETLINEINFOF_COMPONENTTYPE);

/*** GET ***/
mixerLineControls.cbStruct = sizeof(MIXERLINECONTROLS);
mixerLineControls.dwLineID = 1;
mixerLineControls.dwControlType = MIXERCONTROL_CONTROLTYPE_SINGLESELECT;
mixerLineControls.cControls = 1;
mixerLineControls.pamxctrl = &mixerControl;
mixerLineControls.cbmxctrl = sizeof(MIXERCONTROL);
result = mixerGetLineControls((HMIXEROBJ) mixerHandle, &mixerLineControls, MIXER_GETLINECONTROLSF_ONEBYTYPE);


/*** SET ***/
mcdu.dwValue = TRUE;
mcd.cbStruct = sizeof(MIXERCONTROLDETAILS);
mcd.hwndOwner = 0;
mcd.dwControlID = mixerControl.dwControlID;
mcd.paDetails = &mcdu;
mcd.cbDetails = sizeof(MIXERCONTROLDETAILS_UNSIGNED);
mcd.cChannels = 1;
result = mixerSetControlDetails((HMIXEROBJ) mixerHandle, &mcd, MIXER_SETCONTROLDETAILSF_VALUE);