 <p>The main way would be to register the filter file with <code>regsvr32 filter.dll</code> and than create the filter with it's CLSID in your application.</p> <p>If the filter are in the same codebase as the application, you can just create the filter with <code>new</code> and use it.</p> <p>I prefer to load the filter.dll with <code>CoLoadLibrary</code> to get the IClassFactory of the filter and create the filter. You can test this with <a href="http://code.google.com/p/graph-studio-next/" rel="nofollow">GraphStudioNext</a>. You can find sample source code to load a filter this way <a href="http://code.google.com/p/graph-studio-next/source/browse/trunk/src/FilterFromFile.cpp" rel="nofollow">here</a>.</p>