On the source file's property sheet, select the Execution tab. Set the Executor property to Internal Execution. Then right-click the source file's node and choose Copy. Choose Tools > Options. Expand the IDE Configuration node and the Menu Bar node. Right-click the category where you want to place the menu item and choose Paste > Copy.
You can use a similar procedure for adding items to toolbars. The Toolbars node is located below the Menu Bar node.