Can an alocholic have a hot drink to help end a cold?

Short answer: No!

Longer answer, in two parts:

1. Although some might disagree, most experts in the field agree that alcoholics should not drink alcohol at all, for any reason.

2. A hot alcoholic drink does not "help end a cold," although we may think it does because the alcohol makes us notice the symptoms less. Just as much real relief of symptoms can be achieved with a cup of hot herbal tea.

Colds are caused by viruses, and there is no cure for a virus except rest, treatment of symptoms, and allowing the body time to fight it off. The body does the work (when it can) in 6-10 days, although symptoms and fatigue may take longer to abate completely. Some viruses, such as HIV and hepatitis, are not effectively eliminated by the body at all.

Alcohol can actually interfere with the immune system's ability to do its job. I don't expect this to change anyone's mind about the treatment of colds, but it's the straight dope, anyway.