When doing cookies for the first time on any project, I usually do it without any extra settings. I suggest first commenting out the domain, path, and expires settings. Just set the name and value of the cookie and see if you can get that to work. And getting it to work can be tricky, because you need the exact syntax in your http header, especially since you are not using the CGI module. Besides, those settings have default values.

The domain and path are set for the most part as a security or control, to restrict which sites can read the cookie. If you don't specify the domain/path, I believe it will just default to the domain of the site.

If you don't specify an expire time, I believe your browser will default to the duration that the browser process remains active.

Even if you try the CGI module, don't use the domain, path, and expires settings right away until you know you are able to set the cookie.