RTF content in contextmenu strip

I have a requirement- need to display RTF content in context menu. I
am able to host a rich textbox in a contextmenu strip using
ToolStripControlHost class. But assigning some RTF content to the
containing rich textbox control does not display in actual RTF
format- it just dislpays as plain text. Here's the code am using:

//Custom richtextbox to handle bg color in readonly mode
public class MyRichTextBox : RichTextBox
{
public MyRichTextBox()
{
}


public new bool ReadOnly
{
get
{
return base.ReadOnly;
}
set
{
if (value == true)
{
this.BackColor = Color.White;
}


base.ReadOnly = value;
}
}


}


----------------------------------------------------------------
public Form1()
{
InitializeComponent();


m_cmenu.Items.Add(new ToolStripMenuItem("Edit"));
m_cmenu.Items.Add(new ToolStripSeparator());


MyRichTextBox m_richTextBox = new MyRichTextBox();
m_richTextBox.BorderStyle =
System.Windows.Forms.BorderStyle.None;
m_richTextBox.Dock = System.Windows.Forms.DockStyle.Fill;
m_richTextBox.ReadOnly = true;
m_richTextBox.ScrollBars =
System.Windows.Forms.RichTextBoxScrollBars.None;


ToolHost textItem = new ToolHost(m_richTextBox);
//Assign sample RTF content.
m_richTextBox.Rtf = @"{\rtf1\fbidis\ansi
\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fswiss\fprq2\fcharset0
Arial;}{\f1\fnil\fcharset0 Microsoft Sans Serif;}}
\viewkind4\uc1\pard\ltrpar\sa200\sl276\slmult1\f0\fs28 This is\fs22
\i some\i0 \ul Rich\ulnone \b text\b0\par
\pard\ltrpar\f1\fs17\par }";


m_cmenu.Items.Add(textItem);
this.ContextMenuStrip = m_cmenu;//Assign contextmenu for
Form


}