How to add HW mpeg encoder to graph??

I have a AverMedia Cardbus card with hardware mpeg encoder.
I can add the "AverMedia BDA MPEG PS Encoder" to a graph
in graphedit and record MPEG video but am unable to add the encoder
to a graph in my app.

I tried the usual way I add filters

Type t = Type.GetTypeFromCLSID(AverPsMpegEncoderGuid);
AverPsMpegEncoderObject = Activator.CreateInstance(t);
AverPsMpegEncoder = (IBaseFilter)AverPsMpegEncoderObject;

but this doesnt work. Obviously something different must be done
which I have no knowledge of. Can anyone give me a hint at where
I need to start looking to solve this problem?