You need to have experience with Windows APIs. Messenger Plus! adds the ability to its internal JScript language to work with Windows APIs. Everything about the Windows APIs can be found in the
MSDN library. The APIs you need to look for are the menu APIs like 'GetMenu'.
But if you're not experienced in that then it is very difficult to do properly (although the basics are easy). Maybe someone else will write a function for you in that case (if people see this thread)... And if I find some time I might do it myself, but that wont be before next week...