Many times you come across the requirement to add button on list view page for some objects ( Here I am talking about Account Object).
To Add button like I mentioned in the above screenshot, Navigate to Name | Setup | App Setup |Customize | Accounts | Buttons, Links and Actions and then click on New Button or Link. Fill details, you can take help from below screenshot.
Fill the form Label, Name, In Display Type Select “List Button”, Select Behavior as per your choice and in Content Source Select VisualForce Page that you want to open when you click on this button then Click on Save.
Next add this button to list view, to do this Go to “Search Layouts” for Accounts, then edit ” Accounts List View ” and add “Export To Excel” button to selected list buttons.
Now navigate to Account Tab and cheers….