Okay, making the char a pointer did it. Thanks.
For all interested:
Code:
function server_damage(var sender, STRING* msg, var size)
{
	char* data;
	data = _chr(msg);
	
	var victim = data[0];
	var dmg = data[1];
	
	BOOL found = FALSE;
	
	if(ent_player[victim] != NULL)
	{
		if(enet_ent_globpointer(ent_player[victim]) != ANET_ERROR)
		{
			ent_player[victim].armor -= dmg;
			enet_send_skills(enet_ent_globpointer(ent_player[victim]), 24, 24, BROADCAST);
			found = TRUE;
		}
	}
}