AoE Input | Force cast AoE spell

I’ve been wondering this for a while.

Is there a packet which will prompt the client to get input for an AoE spell, as in, the server sends the signal, then the client makes the user select the location to cast the AoE on; Or would there be a way of requesting the AoE input manually?

This has generally been really irritating me to accomplish. Any help would be nice;

Could this have anything to do with it? It’s a rather undocumented packet.