StreamWriter Encoding & MS Word

I cannot install the primary interop assemblies to manipulate word files becuase I have Office XP for Students instead of Pro. I think, MS won't give me an answer? I want to append data to word document. I can do so in Plain Text Format. However, I cannot format the file in any way such as bold or highlight without converting the file into an unwritable format. Is there a way to write to a word file? Encoding option for this or way around? FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write, FileShare.None); string strText = "jlkjlkjlkji"; StreamWriter swFromFileStreamDefaultEnc = new System.IO.StreamWriter(fs, System.Text.Encoding.Unicode); swFromFileStreamDefaultEnc.Write(strText); swFromFileStreamDefaultEnc.Flush(); swFromFileStreamDefaultEnc.Close();