ActiveX, C++ and Asv

I try to build a win app with my Adobe SVG ActiveX.
I just need to have the DOM tree correponding to my SVG file displayed in the ActiveX.

the ActiveX have the function getSVGDocument but with a IDispatch value. Does anybody know how to treat that?
Or anybody know how to have the DOM tree of the ActiveX in a C++ object?

Thanks,

Guillaume