how to make parallel port read data

dear all,
i have one small program reading data from parallel port.

Code:

---

void CProjDlg::OnCalculte()
{
       

    unsigned DataAddress=0x378;
    int DataPort;
    DataPort=_inp(DataAddress);
    m_value=DataPort;
    UpdateData(0);

}

---

but before reading the data, it must setting bit 5 in the port's control register to 1 for reading. how can i do that? thank u