Selectable Weapon Targeting

When building a module for Mutant Chronicles, I needed to add a Gunnery skill for use when shooting Vehicular Mounted Weapons. I added the skill, then changed the Type property of Defense Battery Vehicular Weapon to Gunnery. This changes the underlying skill to Gunnery but defaults the attack target to Melee, thus targeting Parry. The desired outcome is being able to add Gunnery as the underlying skill, and select targeting either of Parry or Target = 4.