This is targeted via the Innate Attack (Gaze) skill.

Call Lightning [131] 
    Innate Attack (Tight Beam Burning, Gaze) 8d [112] 
        Surge, Arcing [+100%] 
        Side Effect (Stunning) [+50%] 
        Overhead [+30%] 
    Innate Attack (Toxic) 1d [18.4] 
        Symptoms (Deafness after 1/3 HP) [+60%] 
        Hearing-Based [+150%] 
        Explosion 3 [+150%] 
    Extended Duration (x30) [+60%] 
        Caster retains ability to call down lightning bolts for 30 seconds 
    Link [+10%] 
    Environmental (Requires a storm) [-40%] 
    Magical [-10%] 
    Spell Components [-20%] 
        Must say "lightning" in Latin 
        Must gesture with hands 
Levels 2-4 [140/148/157] 
    Increase Extended Duration by 1 step [+20%]