There are four ways to do this:
1. Are you just wanting access to the code by clicking a button? If so, draw an object on the spreadsheet, right-click and choose "Assign Macro".
2. Or do you want a button on the toolbar? Right-click the toolbar, choose "Customize". In dialog box, choose middle tab "Commands", on the left side scroll down to "Macros", select and then on right side choose "Custom Menu Item", click-drag it up to the toolbar, and relase when you see the dark vertical line. Then right-click the button, and choose "Assign macro". Right-click again and choose "Name" and put your custom name there.
3. Or Forms toolbar buttons?
4. Control Toolbox buttons?
Each has advantages.