BCB开发的OCX潜入到网页中,OCX怎么获取属性值

BCB开发的OCX潜入到网页中,OCX如何获取属性值?
比如在网页中:
  <OBJECT
classid="clsid:FCBE3774-1A27-4799-88E8-6AA1A9741ACD"
codebase="ActFrmProj1.inf#version=1,0,1,3"
width=100%
height=400
align=center
hspace=0
vspace=0
  file="one.wrl"
  id="myocx"
  >
上面的file是自己定义的属性,当网页载入时,程序中如何获取"one.wrl"字符串值?

------解决方案--------------------
C/C++ code

STDMETHODIMP TWTImpl::get_Property1(BSTR* Value)
{
  try
  {
    *Value   =   WideString(m_VclCtl->pa1).Copy();
  }
  catch(Exception &e)
  {
    return Error(e.Message.c_str(), IID_IWT);
  }
  return S_OK;
};


STDMETHODIMP TWTImpl::set_Property1(BSTR Value)
{
  try
  {
      m_VclCtl->pa1   =   (AnsiString)Value;
  }
  catch(Exception &e)
  {
    return Error(e.Message.c_str(), IID_IWT);
  }
  return S_OK;
};