Adding Submenu on header menu from GridPanel

Hello Folks,

I'd like o to add a kind of "Submenu" on the header menu from my GridPanel.
Functionally i want to use this new submenu as a path to insert data into all column cells.
Basically I need a component to select data to be inserted in column cells.
The data offered by submenu should contain the same data presented as an option for insertion of individual cells.
I hope I have been clear on my explanation.

Is there a way to perform the described functionality?

Thanks in advance,