Declare Function SendMessage Lib "User" _
  (ByVal hWnd As Integer, ByVal wMsg As Integer, _
  ByVal wParam As Integer, lParam As Any) As Long

Sub CBFindString(ctlEdit As Control, sSearch As String)
  Dim lPos As Long
  Const CB_FINDSTRING = &H40C
  lPos = SendMessage(ctlEdit.hWnd, CB_FINDSTRING,  0 , ByVal sSearch)
  If lPos >= 0  Then ctlEdit.ListIndex = lPos
End Sub

Option Explicit
 #If Win32 Then  ' 32-разрядная версия VB
   Private Const LB_FINDSTRING = &H18F
   Private Declare Function SendMessage Lib _
     "User32" Alias "SendMessageA" (ByVal hWnd _
     As Long, ByVal  wMsg As Long, ByVal wParam _
     As Long, lParam As _ Any) As Long
 #Else  ' 16-разрядная версия VB
   Private Const WM_USER = &H400
   Private Const LB_FINDSTRING = (WM_USER +  16 )
   Private Declare Function SendMessage Lib _
     "User" (ByVal hWnd As Integer, ByVal wMsg _
     As Integer,  ByVal wParam As Integer, lParam _
     As Any) As Long
 #End If

Private Sub Form_Load()
  List1.AddItem "Апельсин"
  List1.AddItem "Банан"
  List1.AddItem "Яблоко"
  List1.AddItem "Персик"
  List1.AddItem "Ананас"
  List1.AddItem "Авокадо"
End Sub

Private Sub Text1_Change()
  Dim pos As Long
  List1.ListIndex = SendMessage(List1.hWnd, _
    LB_FINDSTRING, - 1 , ByVal CStr(Text1.Text))
  If List1.ListIndex = - 1  Then
    pos = Text1.SelStart
  Else
    pos = Text1.SelStart
    Text1.Text = List1
    Text1.SelStart = pos
    Text1.SelLength = Len(Text1.Text) - pos End If
End Sub

Private Sub Text1_KeyDown(KeyCode As Integer, Shift As Integer)
  '
  On Error Resume Next
  If KeyCode =  8  Then ' Backspace
    If Text1.SelLength <>  0  Then
      Text1.Text = Mid$(Text1,  1 , Text1.SelStart -  1 )
      KeyCode =  0 
    End If
  ElseIf KeyCode =  46  Then ' Del
     If Text1.SelLength <>  0  And _
       Text1.SelStart <>  0  Then
       KeyCode =  0 
    End If
  End If
End Sub