constant current control

We a constant current controller designed that will need to provide a constant current to a pulsed load which will consist of 0.1mS ON and 0.9mS OFF or longer. The regulator must control the output voltage control the current to 0.01A with a maximum output voltage of 12V and output current of 5A. The actual current during the ON time must be displayed on a digital amp meter. There must also be a method for the user to set the current. I not possible to read amperage while pulsing then we can just read what we "set" the amperage to.