Many people need to use their mouse a lot; resulting in pain, numbness, and/or cramping to name a few. Try to alternate tasks and take breaks as much as possible, but also try using your mouse in your other hand. This takes some practice, but can be quite relieving to your regular mousing hand. To change the mouse button commands in Microsoft Word 2003, go to Control Panel > Mouse > Buttons. Also, try making your own shortcut keys to increase keyboard use over mouse use – go to View > Toolbars > Customize > Commands >Keyboard. Select the shortcut you want to make from the menu and customize the keyboard keys to your needs.