I want to change the handle..
..So that it is enabled, but doesn't appear. How can I do this?
I am using the Gnome Global Menu Applet by the way.
I don't know why do you need to do that but in the image you provide the handle is right there as you can see when paying attention to the same image with a little amplification:
In that image the handle seems not to be there but it is because of a visual effect by the theme that you are using.
If you wish to remove the handle simply right clic over the global-menu and choose "Preferences", then go to the "Applet" tab and enable or disable "Add a handle to this applet" as seen in the next screenshot:
Sorry, I am using a spanish system at the moment so I may change the image tomorrow, and the "Add a handle to this applet" text may differ.
The options in your applet depends on the version that you use. Updating to the new version will give you this options. After installing and placing the applet in your panel remember to reboot in order to gain access to all the features in the preferences window.