For future reference: if you’re using Javascript and want to convert a decimal entity in HTML (Đ, for example) to the Unicode character it represents (“Đ”), this works:

// converts "fiancé" to "fiancé", etc.

newstr = oldstr.replace(/&#([0-9]*);/,
            function(full, charcode) {
                return String.fromCharCode(charcode);
            });

The full parameter is ignored; we want the second one, charcode, which is the first backreferenced match in the regex (the character code).