You can use the keyboard to control the little man. By default, the keys from the keypad are configured for the game. However you can customize the key mappings in the Keyboard tab in the Preferences dialog. To select a different key for a command, double-click on the line for that command and then press the key you want to use.
By default, you use the numeric keypad on the right-hand side of the keyboard (not the separate arrow keys).
You may need to switch off the NumLock to make these work.