use pubs
go

create procedure dbo.usp_Test
   @I int
 , @O int out
as set nocount on
   set @O = @I +  1000 
   return   @I -  1000 
go

int main(){
  _bstr_t ConnStr = "Provider=SQLOLEDB;    \
                     Data Source=(local);  \
                     Initial Catalog=pubs; \
                     Integrated Security=SSPI";

  _ConnectionPtr conn;

  try {
    conn.CreateInstance(__uuidof(Connection));
    conn->Open(ConnStr,"","",adConnectUnspecified);

    _CommandPtr cmd;
    cmd.CreateInstance(__uuidof(Command));
    cmd->CommandType    = adCmdStoredProc;

    ParametersPtr pars = cmd->Parameters;
    pars->Append(cmd->CreateParameter("@RETURN",adInteger,adParamReturnValue, 0 , 0 ));
    pars->Append(cmd->CreateParameter("@I",     adInteger,adParamInput,       0 , 0 ));
    pars->Append(cmd->CreateParameter("@O",     adInteger,adParamOutput,      0 , 0 ));

    cmd->CommandText      = "dbo.usp_Test";
    cmd->ActiveConnection = conn;

    pars->Item[1L]->Value = long( 23 );
    cmd->Execute( 0 , 0 ,adOptionUnspecified);

    std::cout << " R " << long(pars->Item[0L]->Value) << std::endl;
    std::cout << " O " << long(pars->Item[2L]->Value) << std::endl;

  }catch(_com_error &e){
    std::cerr << " Error " << (const char*)e.Description() << std::endl;
  }
. . .