The Jump to Help Topic menu option is used to display a specific topic of the Q++ Help, when you are given its internal topic number. To do so, use the Help > Jump to help topic menu sequence, type in the help topic number, and click OK.

You will rarely need to use this functionality, since most of the accesses to the Q++ Help come automatically through its context sensitive integration with Q++. But in some cases it may be easier for technical support to refer you to the precise number of a help topic, than to try to explain where to find that topic (there are over 2000 help topics).
This feature is also used to get more information on token errors in the script preview.