What to do with NIL response for legacy filter 'Wav Dest' in Delphi 6 DSPACK program?

I am trying to create a Delphi 6 program with DSPACK that records audio from the PC input devices (Windows XP) and then writes the captured audio to a MS format WAV file. The problem I am having is that I am getting NIL back when I try to get the legacy filter named 'WAV Dest':

CapEnum开发者_开发技巧.SelectGUIDCategory(CLSID_LegacyAmFilterCategory); 
filWaveDest.BaseFilter.Moniker := CapEnum.GetMoniker(CapEnum.FilterIndexOfFriendlyName('WAV Dest')); 

filWaveDest.BaseFilter.Moniker contains NIL after these calls. How can I correct this since obviously subsequent code that attempts to write the WAV data captured using filWaveDest fails?

Wav Dest is not a standard DirectShow filter. It is an example filter in the SDK. Either build the object or download a copy of the DLL someone else has built.