To add your own User Defined Commands to the menu you need to start the Menu Customization editor from the Configuration menu.
This will list all of your User Defined Commands on the left and on the right will show your user-defined menus.
The menu is shown as a tree list with the top level being menus on the menu bar.
You can drag and drop menu items in the tree list to rearrange how you want to display items.
The Add Menu button adds a new top-level menu or sub-Menu.
Select the User Defined Command you want to add on the left, and select under which menu you want that command added on the right. Then press the "-->" to add that command to the menu tree.