Does this managed C++ code always work? another solution?

void Function( System::Guid clsid )
{

   Guid* __pin * pClsid = &clsid;
   REFCLSID refClsid = (REFCLSID) *pClsid;

   UseRefClsid(refClsid);

}

void UseRefClsid( REFCLSID clsid )
{
   ...
}