Step 1: Defining two Names to be used in a Combo Box:
1. Add a list of months to a new sheet, select cell A2, and then press Ctrl+Shift+Down Arrow to select the list.
2. Press Ctrl+F3 and define the Name MonthsList.
3. Select cell B2, press Ctrl+F3 and define the Name MonthSelectionNumber.
Step 2: Adding a Combo Box:
1. In the sheet where the report is being created, place the mouse arrow over any toolbar, right click, and then select Forms from the shortcut menu.
2. Click the Combo Box icon. The cursor changes into a cross.
3. Select a cell in the sheet, and draw the shape of the Combo Box. When you are finished, a Combo Box appears.
4. Select the Combo Box you just created and make sure you are in edit mode (see the small circles in the screenshot below).
5. Right-click, and select Format Control from the shortcut menu.
6. Select the Control tab.
7. In the Input Range box, type the previously defined Name, MonthsList.
8. In the Cell Link box, type the defined Name, MonthSelectionNumber.
9. Select the 3-D shading checkbox, and click OK.
Screenshot // Adding a Combo Box