Hotkey for MFC Ribbon QAT dropdown menu

Hi everyone,

Is there a hotkey has been assigned to open the dropdown menu of QAT? Normally, you can use ALT or F10 to start a key sequence to select a command in a Ribbon bar. It looks like several numbers have been assigned to the commands in QAT, but no key has been assigned to the dropdown menu. Is it possible to assign a key to the dropdown menu?

Thanks.