Toolbar Buttons In Help Files - Help Authoring Site
Removing the standards buttons is not supported. Adding buttons can be done but not in the second window. If you are using HCP then buttons cannot be put in second window anyway.
You define the buttons in EASYHELP.INI. This requires a more detailed knowledge of the Help Compiler though. Once you have defined them you can use then in any project by listing them by name in the advanced options. Again this is advanced , shame you can't attend one of our courses:-)
Here are some examples...
This is the name you would use in your project. Separate multiple button names with commas (e.g. print,exit)
Let us know what you want the button to do and we can send you a definition to use.