Worker thread in VC++ 6

I have the following code below that apears to be working.
I have not included all the serial port initialization here.
When I receive a 30h or 31h or 32h into the serial port it does display the
correct "Got ##h" message.
Now how do I get the data (Bar[0]) to "UpdateDisplay()" ?
Bar[] is a global varible;
I checked the task manager and I do not seems to be wasting any CPU cycles.
Thanks
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void CMartin1Dlg::UpdateDisplay()
{
  m_BarChart.SetNumData(33);
  m_BarChart.SetData(1,Bar[0]);
  m_BarChart.Invalidate();
}

UINT WorkerThreadProc( LPVOID Param ) //Sample function for using in
AfxBeginThread
{
  int DataByte=0x00;
  int Count=0;

loop:
  while(Count == 0){
    Count = Port.BytesInReceiveBuffer();
    Sleep(100);
  }
  DataByte=Port.GetByte(18);
  if (DataByte == 0x30){
    Bar[0]=0;
    AfxMessageBox("Got 30h");
  }
  if (DataByte == 0x31){
    Bar[0]=10;
    AfxMessageBox("Got 31h");
  }
  if (DataByte == 0x32){
    Bar[0] ;
    AfxMessageBox("Got 32h");
  }
  goto loop;

  return TRUE;
}