Try equipping it in the actual editor, then use the evolution cheat that lets you choose any creature in Sporepedia... I believe your having the same problem I had. Also you know how there are sections in the editor for Mouth, Eyes, Legs, Arms, Feet, Graspers, etc? YOu might notice a very small arrow, if you click on that you should be able to move over to the staff page. It's the very first item that appears on that staff page.
Spammers beware, the wrath of Sparta is near.