Enable OWA on another website

I am using Host Header Names to host multiple websites from one IIS Server with one public IP address. I have a site “http://corp.my_domain.com”. I want to access OWA at “http://corp.my_domain.com/exchange” instead of at the default site address. How do I set this up? I’m working with Exchange 2000, Windows 2000 Server and IIS 5.0.
MS Knowledge Base Article #261953 covers this issue for Exchange Server 5.5, but I can’t find an article for Exchange 2000.