Embed Font into RichTextBox

Hi, I am trying to embed 'Telugu' font into richtextbox to display text in 'Telugu' pulling from a word document, it embeds font but I still see the text as junk (few words are showing in telugu, can any please help me resolve this issue. Here is my code

Microsoft.Office.Interop.Word.Application wrd = new Microsoft.Office.Interop.Word.Application();
object miss = System.Reflection.Missing.Value;
object path = @"C:\Sample\XYZ.docx";
object readOnly = true;
Microsoft.Office.Interop.Word.Document docs=wrd.Documents.Open(ref path, ref miss, ref readOnly, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss, ref miss,ref miss, ref miss, ref miss, ref miss);
string totaltext = "";
for (int i = 0; i < docs.Paragraphs.Count; i++)
{
totaltext+=" \r\n "+ docs.Paragraphs[i+1].Range.Text.ToString();
}
PrivateFontCollection pv = new System.Drawing.Text.PrivateFontCollection();
pv.AddFontFile("C:\\Sample\\Hemalatha.ttf");
rTxtDoc.Font = new Font(pv.Families[0], 10, FontStyle.Regular);
rTxtDoc.Text = totaltext;
docs.Close();
wrd.Quit();

Thanks in advance

GP_T