Xerces: DOM document object from VB.Net2005 to DOM document object in MFC DLL (VC++.NET 2005)

Hello all,
I have two applications, one in MFC(VC++.NET 2005) and one in VB.NET 2005. I need to use functions from both. I am facing a problem as below:

I have a function in VB.NET

Public Function Write(ByRef doc As Xerces.IXMLDOMDocument, ByRef element As Xerces.IXMLDOMElement) As String

         Write_DLL(doc, element) // MFC function call

    End Function

and a function in VC++.Net 2005 (MFC)

extern "C" __declspec( dllexport ) char* Write_DLL(xercesc_2_8::DOMDocument* pDoc, xercesc_2_8::DOMElement* pElem)
{
      //wants to use pDoc here
}


and I want to pass a DOM document object from VB.Net2005 to function(DOM document object) in MFC (VC++.NET 2005),
when I call Write_DLL(doc, element)  then there is some error
I am not sure how I can do this task. can any one tell me how I can  pass a DOM document object from VB.Net2005 to function(DOM document object) in MFC (VC++.NET 2005) and vice versa?
--
Regards,
Arshad