Capturing Mouse Clicks and Updates on a Control (newbie)

Hello, I'm creating some CComboBoxes at runtime, as I don't know how
many I'll need, it depends on the data entering the parent dialog.

So I declare a member variable in my Dialog to hold my CComboBoxes:

CComboBox *combos[10];

Then, in the OnInitDialog(), is do this:

for(int i=0;i<nCombos;i++){
  combos[i] = new CComboBox;
  rect.top = 1; rect.bottom = rect.top + 240; rect.left = 0; rect.right
= 100;
  if(!combos[i]->Create(CBS_DROPDOWNLIST | CBS_SORT | WS_VISIBLE |
WS_TABSTOP | WS_VSCROLL, rect, this, i))
  {
    TRACE(_T("Failed to create combo-box\n"));
    return FALSE;
  }

  combos[i]->AddString("Example text");
  combos[i]->AddString("More text..");
  combos[i]->SetWindowPos(NULL, 200, i*30, 0, 0, SWP_NOZORDER |
SWP_NOSIZE);
}

This is creating them ok. However, I want to know how to handle changes
in selection etc, as I want to enable / disable certain boxes depending
on the selections in each box. Also, I was unsure what to put in the
4th parameter of the Create() function.

Can anyone help?