Use API calls to set the ComboBox's list index while avoiding unwanted Click events. This program uses a cComboHelper class. When a ComboBox gets focus, the program attachs one of these objects to it.

Private moCombo As cComboHelper

Private Sub cboFlintstones_GotFocus()
  moCombo.AttachTo cboFlintstones
End Sub

Private Sub cboSimpsons_GotFocus()
  moCombo.AttachTo cboSimpsons
End Sub

Private Sub moCombo_KeyPress(KeyAscii As Integer)

  'Remarks : 1. When the user types something into the text
  ' portion, move to the first
  '             list entry which begins with the displayed
  ' text.
  '          2. Not all keys trigger this event. In
  ' particular -
  '
  '               {Delete}    ... triggers KeyDown but not
  ' KeyPress
  '               {BackSpace} ... triggers KeyPress but not
  ' KeyDown
  '
  '          3. This code was originally in the Change()
  ' event, but confusing
  '             interactions kept occurring (list index was
  ' being set to -1 by Windows)
  '
  Dim sSearchOn As String                                 _
      'current string to search on

  On Error Resume Next

  'These keys can trigger this event, but are of no
  ' interest to us ...
  If KeyAscii = vbKeyReturn Or KeyAscii = vbKeyTab Then
    GoTo Bye_moCombo_KeyPress                             _
        'we don't want to know
  End If

  'So a content-modifying key was entered; decide what to
  ' search on...
  sSearchOn = ResultingText(KeyAscii)
  
  'Perform the search; if it resulted in a move, cancel the
  ' key input...
  If KeyAscii = vbKeyBack Then                            _
      'prevent re-finding original !
    If SearchOn(sSearchOn, CB_FINDSTRINGEXACT) = True Then _
        KeyAscii = 0
  Else
    If SearchOn(sSearchOn, CB_FINDSTRING) = True Then _
        KeyAscii = 0
  End If
  
Bye_moCombo_KeyPress:
  Exit Sub

End Sub

Private Function SearchOn(ByVal sStartText$, ByVal _
    iMatchType%) As Boolean

  'Purpose : Searches the combo and relocates if a match is
  ' found
  '
  'Returns : Whether a move occurred - True or False
  '
  'Remarks :
  '
  Dim mOriginalIndex As Long
  Dim mNewIndex As Long
  Dim yMoveOccurred As Boolean
  
  On Error Resume Next
  mOriginalIndex = moCombo.ListIndex
  yMoveOccurred = False
  
  'Determine our start index for searching...
  mOriginalIndex = mOriginalIndex - 1
  If mOriginalIndex < -1 Then mOriginalIndex = -1
  
  'Perform our search...
  With moCombo
    If Len(sStartText) > 0 Then                           _
        'if it contains any text
      mNewIndex = MatchingRow(sStartText, mOriginalIndex, _
          iMatchType)
      If mNewIndex <> -1 Then                             _
          'match found
        SendMessageByString .hwnd, CB_SETCURSEL, mNewIndex, _
            0    'set list index
        .SelStart = Len(sStartText)
        .SelLength = Len(.Text) - Len(sStartText)         _
            'select the bit AFTER the match
        yMoveOccurred = True
      End If
    Else                                                  _
        'contains no text
      SendMessageByString .hwnd, CB_SETCURSEL, -1, 0      _
          'set list index to -1
      If mOriginalIndex <> -1 Then yMoveOccurred = True
    End If
  End With
  
  SearchOn = yMoveOccurred

End Function