adding outside light

[gg1a]

i want to add outside light to existing switch, in garage , i have a switch that operates 3 lights and 1 off those lights is also controlled by another double switch at garage door 1 cable in com and 1 in l1 and l2 the other switch / com and l1 and l2 has no cable this is one i intend to use
i would rather do away with controlling the light by 2 different switches if means getting outside light on
help would be appreciated