Yes, I am aware of that.
But my plugin has 23 functions as of now in three main menus and that is a lot of configuring and almost impossible to remember all.

Having remembered two or three Alt+"some letter" for opening main plugin menus would be simpler.
What I would need is something like that:

&&cMyMenu

... where "c" letter would not be visible, but would open a menu when pressed after Alt.

Thanks for answer anyway.