Find faster a String in Combo or ListBox while typing (Using SendMessage API)

Private Sub Combo1_KeyPress(KeyAscii As Integer)
 Dim CB As Long
 Dim FindString As String
 Const CB_ERR = (-1)
 Const CB_FINDSTRING = &H14C
 If KeyAscii < 32 Or KeyAscii > 127 Then Exit Sub
 If Combo1.SelLength = 0 Then
 FindString = Combo1.Text & Chr$(KeyAscii)
 Else
 FindString = Left$(Combo1.Text, Combo1.SelStart) & Chr$(KeyAscii)
 End If
 CB = SendMessage(Combo1.hWnd, CB_FINDSTRING, -1, ByVal FindString)
 If CB <> CB_ERR Then
 Combo1.ListIndex = CB
 Combo1.SelStart = Len(FindString)
 Combo1.SelLength = Len(Combo1.Text) - Combo1.SelStart
 End If
 KeyAscii = 0
End Sub