The help and setfunhelp functions provide access to the product and your custom help files.
You can use the help function to display a Help file. Depending on the Help file's extension, the help function displays the appropriate viewer for the specified file. The following example code displays the LINE commands topic in the default AutoCAD Help file.
(help "" "line")
You can create a custom Help file that provides information about your applications and display it with the help function. The following example code displays a custom help file named abcindoorcad.chm:
(defun C:ABCINDOORCADHELP () (help "abcindoorcad.chm") (princ) )
The setfunhelp function provides contextual help for user-defined commands. After the definition of a new command defined with AutoLISP, add a call to setfunhelp and associate a specific help topic to the command. The following example assigns the help topic “MyCommand” in the abcindoorcad.chm file to the user-defined MYCOMMAND command:
(defun C:MYCOMMAND ( ) .. Command definition .. ) (setfunhelp "c:mycommand" "abcindoorcad.chm" "mycommand")