executeMenuCommand(), as the name implies, executes a command from a menu (File, Edit, Object, et cetera). Most of these commands have shortcuts, but to execute a command through a script, you need to specify the command to be executed. For example
zooms in (Ctrl+plus) and
groups selected items (Ctrl+G). So what you need is the parameter representing the command, not the command's shortcut. What commands are you looking to execute?