richtextbox... cursor position

From DB, i get a field which contains data in richtextformat. actually the data is an image. it was uploaded to DB from a richtextbox. so when i get it from DB, it is like a richtext content. i want to insert this image at a given cursor location. BUt the code below i  am using is inserting image at last line. please correct me.

data from DB is extracted thru Datareader reader2. richtextbox name is rcheditor1.

while (reader2.Read())

String test = reader2[0].ToString();

string Field2 = string.Empty;

}