URL format:

<Help address>/index.htm?page=<topic filename>

For example:

Assume the address of your Web help is http://www.myweb.com/help/index.htm , if you want to link to a topic "Introduction" which its file name is "introduction.htm", you can use this URL:http://www.myweb.com/help/index.htm?page=introduction.htm

You can also right-click the right frame of your Web Help, choose Properties on the popup menu and then get the address from Address(URL) section. This address will automatically redirect to the URL above.