|Yes, it's possible.|
You can assign a macro to any shape or picture that you place on a worksheet just by right-clicking the object and selecting Assign Macro.
You can also add a button or menu item by using the Tools...Customize...Commands Tab.
Scroll down to Macros and click on it. Drag the button or menu item to wherever you want it and, with the Customize window still open, right-click it and select Assign Macro.
You can also edit the button image or text as long as you have the Customize window open.