I believe this question was asked for many times but I cannot find answers(((

So, I need to update contents of menu popup just before it is activated. For example, I need to refresh most recently used files list when user select "Open Recent" in main menu.
I don't want to update this popup every time new file is open - this is just wasting processor time. I want to update it when user ask for it.

But with commands like ON BAR or ON PAD I just can activate popup but cannot refresh it. I tried to associate my procedure with ON BAR insted of ACTIVATE POPUP. But if I use ACTIVATE POPUP in my procedure then the popup appears separated from main menu.

So the question is simple: Is it possible to do ON BAR ... ACTIVATE POPUP and update popup just before it is activated?