Just make sure that your HTML file is encoded with UTF-8 and that your web server sends a HTTP header with that charset, then you just can write that character directly into your HTMl file.
http://www.w3.org/International/O-HTTP-charset
If you can't use UTF-8 for some reason, you can look up the codes in a unicode list such as http://en.wikipedia.org/wiki/List_of_Unicode_characters and use ꯍ
where ABCD is the hexcode from that list (U+ABCD).