(Not sure if this applies to Word 2007 or 2010)
Add a command to a Menu
Make sure the toolbar you want to change is visible.
On the View menu, point to Toolbars.
Click Customize
Click the Toolbar Options arrow
Click the Commands tab
In the Categories box, click a category for the command you want the button to perform. (Insert)
Drag the command (Symbol) from the Commands box and while holding down the left mouse button hover over the Insert Menu until it drops down. Then position Symbol on this menu and let up on the left mouse button
On the Customize dialog box, click Close.
(http://en.allexperts.com/q/Microsoft-Word-1058/symbols-box-1.htm)
