How to send MIDI out

Hi all,
Can someone explain me how to send a MIDI out command for leds.
Wich command do u use and what values etc do i set for:
CC18 (play/pauze) led
Can someone explain me how to send a MIDI out command for leds.
Wich command do u use and what values etc do i set for:
CC18 (play/pauze) led