Hi Mark1122334455667788 and welcome to our community
RoboHelp in and of itself doesn't offer this. But if you are
creative, you can make it happen. Exactly how could depend on what
your target output is. For example, fellow Adobe Community Expert
Roger Nilsson has developed a method using browser cookies. He has
info on his site about it.
Click
here to visit Roger's site and read about the cookie solution.
If you are developing .CHM based help, I've implemented a method
whereby you use a Shortcut control to open an instance of Windows
Notepad and looking for a specific document file name.
Hopefully something here was helpful... Rick