Link to a topic in another project (in a new window)

You can use a shortcut control to start up a new hh.exe process, feeding it the path to the help topic you want to call. Use the Hidden (for Scripts) form of the control, and place it at the end of the topic. Change your link to javascript:UniqueId0.Click() (where UniqueId0 is the ID attribute of the shortcut control) and it will run the shortcut when clicked.

But there is a bug with this in Adobe RoboHelp HTML 8, which you can find a discussion of over in the RoboHelp HTML forum. ARH8 omits the ID attribute, making it impossible to run the link. I worked around this problem by wrapping my object in javascript so that ARH8 cannot mess it up. The result looks like:

<script language="JScript" type="text/javascript">//<![CDATA[
  document.writeln('<OBJECT CLASSID="clsid:ADB880A6-D8FF-11CF-9377-00AA003B7A11"');
  document.writeln(' ID="UniqueId0"  TYPE="application/x-oleobject">');
  document.writeln('<PARAM NAME="Command"  VALUE="Shortcut">');
  document.writeln('<PARAM NAME="Font"  VALUE="MS Sans Serif,8,0,,">');
  document.writeln('<PARAM NAME="Item1"  value=",hh.exe,helpfile.chm::/topic.htm">');
  document.writeln('</OBJECT>');
//]]></script>

Alternatively, if having this link look like a button is OK with you, then you can just use the form of the control that makes a button and put it exactly where you want the link to be. This doesn't require the ID tag so should work in ARH8.