i have program to read data from microcontroller using MSCOMM. i want setting input buffer into 1 byte. but I cant but change it.
this is my program

Code:
void CStripDlg::OnOpen() 
{
	// TODO: Add your control notification handler code here
		TRY
	{
	m_comm.SetCommPort(12);
	m_comm.SetSettings("9600,N,8,1");
	m_comm.SetInputLen(1);
	m_comm.SetRTSEnable(TRUE);
	m_comm.SetRThreshold(4);
	m_comm.SetInBufferSize(1);
	m_comm.SetPortOpen(true);


	UpdateData(FALSE);
		MessageBox("Port opened successfully");
	}
	CATCH(CException, e)
	{
		MessageBox("Error opening port");
	}
	END_CATCH
void CStripDlg::OnTimer(UINT nIDEvent) 
{
	// TODO: Add your message handler code here and/or call default
		int dcount=0;
		CString data[4];
		VARIANT in_dat;
if(m_comm.GetCommEvent()==2)
	{
			in_dat = m_comm.GetInput();
			CString strInput(in_dat.bstrVal);

			if(strInput == "*")
			{
			for(dcount=0; dcount<=2;dcount++)
			{
				in_dat = m_comm.GetInput();
				CString strInput(in_dat.bstrVal);
				data[dcount] = strInput;
			}
			double z = Asc(data[0]);
			double x = Asc(data[1]);
			double y = Asc(data[2]);

			double a = hitung(z, data[0]);
			double b = hitung(x, data[1]);
			double c = hitung(y, data[2]);
			
			double hasil = ((a*256)+(b*16)+c);

			m_input.Format("%s%s%s%s | %0.f ", strInput, data[0], data[1], data[2], hasil);
			
			m_chart.Set_y(hasil);
			m_gambar.Set_y(hasil);
			m_comm.SetInBufferCount(0);
			}
	}
			UpdateData(FALSE);
	CDialog::OnTimer(nIDEvent);
}