There used to be a "Help File" editor but that was so insanely good as an idea that in their infinite wisdom, Microsoft doesn't push that much. The last time I did this, I might have done a SMALL amount of overkill, but...
I built a Word file and assured that it had short-text bookmark names. Then I built a subroutine (in a general module) that would open a specified WORD file in Read-Only mode, execute a JumpTo Bookmark operation, and would seek the bookmark associated with data specific to the control I had just clicked to get that help.
Then I put "hot spots" with question marks in them next to some controls. Each such hot spot responded to an OnClick operation and would call that module. The subroutine would know whether it had ever been called before in the current session and would pop up a message box if not. The first time you asked for help in a session, it would say, "If you open a help article, remember to click on the CLOSE button in the upper right of the help window." After that, it just popped up the help article that was found at the given bookmark.