richtextbox的新添加指定文字变色和项目符号实现问题，说的够详细的吧，希望帮帮忙，给50分

Private Sub Command2_Click()

RTextBox1.SelStart = Len(RTextBox1.Text)
RTextBox1.SelLength = 0
RTextBox1.SelBullet = True
RTextBox1.SelColor = vbRed
RTextBox1.Text = RTextBox1.Text & vbCrLf "new word"

RTextBox1.SelBullet = False
End Sub

Private Sub RTextBox1_Change()
If LenB(RTextBox1.Text) > 50000 Then
RTextBox1.SelStart = Len(RTextBox1.Text) - 2000
RTextBox1.SelLength = 2000
Dim sel As String
sel = RTextBox1.SelText
RTextBox1.Text = sel
End If
RTextBox1.SelStart = Len(RTextBox1.Text)
RTextBox1.SelLength = 0
End Sub

以上的代码无法实现“new word”变红色，和有项目符号，请问应该怎么写程序？