In order to make these symbols you must use the numeric keypad on the right side of the keyboard. The numbers on the top row of your keyboard will NOT work. First, activate the numeric keypad by pressing the "NUM LOCK" key.
Next enter the sequence of numbers while holding the Alt key down. You MUST enter the beginning zero along with the other numbers in the sequence.
Below are a few common symbols not found on the keyboard and how to make them.
#number - - - Symbol produced - Hold the Alt key down while entering the numbers
0169 - - - - -©
0174 - - - - -®
0163- - - - -£
0191 - - - - -¿