Skill instead of target, being splash with collision

[h3drix]

good morning good afternoon or good night

Does anyone by any chance know how to do such a thing?
Put the ability as splash and it hits the first target it passes in front of.

For example, placing an ice barrier in front of a player and when you cast the ability, it hits the barrier and not the player behind it like this:
https://i.imgur.com/sH5qtRC.png

I found this in skill.c, but is this really where I should move?

void skill_attack_blow(struct block_list *src, struct block_list *dsrc, struct block_list *target, uint8 blewcount, uint16 skill_id, uint16 skill_lv, int64 damage, unsigned int tick, int flag) {
int8 dir = -1; // default direction
//Only knockback if it's still alive, otherwise a "ghost" is left behind. [Skotlex]
//Reflected spells from not bounce back (src == dsrc since it only happens for direct skills)