各位高手,請求一個Rich Edit Controller 的問題 ?(編號:1681)

我想寫一個能在 Rich Edit Controller 中 ,任意改變某些文字的背景顏色的程式.即給 (座標,背景顏色) 便可由程式來做.
下列程式,不曉得那裡錯了,煩請指正,謝謝!
Type LogFont
lfHeight As Long
 lfWidth As Long
 lfEscapement As Long
 lfOrientation As Long
 lfWeight As Long
 lfItalic As Byte
 lfUnderline As Byte
 lfStrikeOut As Byte
 lfCharSet As Byte
 lfOutPrecision As Byte
 lfClipPrecision As Byte
 lfQuality As Byte
 lfPitchAndFamily As Byte
 lfFaceName(LF_FACESIZE - 1) As Byte
End Type
Public nfont As LogFont
Type Charformat2
cbsize As Long
  dwMask As Long
  dwEffects As Long
  yHeight As Long
  yOffset As Long
  crTextColor As Long
  bCharSet As Byte
  bPitchAndFamily As Byte
  szFaceName(LF_FACESIZE - 1) As Byte
  wWeight As Integer
  sSpacing As Integer
  crBackColor As Long
  lcid As Long
  dwReserved As Long
  sStyle As Integer
  wKerning As Integer
  bUnderlineType As Byte
  bAnimation As Byte
  bRevAuthor As Byte
  bReserved1 As Byte
End Type

Public Sub SetCharFormat(ByVal ObjHwnd As Long, ByVal TextColor As Long, ByVal Bkcolor As Long)
 Dim result As Long, Charformat As Charformat2
 Dim FaceName As String
 
 
 Charformat.cbsize = LenB(Charformat)
 result = SendMessage(ObjHwnd, EM_GETCHARFORMAT, 1&, Charformat)
 Const SET_Mask = CFM_COLOR Or CFM_BACKCOLOR
 Charformat.cbsize = LenB(Charformat)
 Charformat.dwMask = SET_Mask
 Charformat.crTextColor = TextColor
 Charformat.crBackColor = Bkcolor
 result = SendMessage(ObjHwnd, EM_SETCHARFORMAT, SCF_SELECTION, Charformat)
End Sub

然後在Command1 中 Call SetCharFormat(text1.hwnd,&hff,&hff00)