The rules defining how to build a URL based on a help ID are kept behind an interface:

public interface IOHManager
{
    /** returns the URL for the page to be opened. */
    public String getOnlineHelpURL(String project,
                                    String page,
                                    String helpId,
                                    String language);
}

You can write your own implementation of this interface in which you apply your rules. The result must be a valid URL which is opened inside a pop-up.

For more details, see the Java API documentation for the package com.softwareag.cis.onlinehelp.