I remember in eAthena you can also change the @go list:
this was from my old eA svn I wonder where it is now on rA:
// if no value, display all value
if (!message || !*message || sscanf(message, "%11s", map_name) < 1 || town < 0 || town >= ARRAYLENGTH(data)) {
clif_displaymessage(fd, msg_txt(38)); // Invalid location number, or name.
clif_displaymessage(fd, msg_txt(82)); // Please provide a name or number from the list provided:
clif_displaymessage(fd, " 0=Prontera 1=Morroc 2=Geffen");
clif_displaymessage(fd, " 3=Payon 4=Alberta 5=Izlude");
clif_displaymessage(fd, " 6=Al De Baran 7=Lutie 8=Comodo");
clif_displaymessage(fd, " 9=Yuno 10=Amatsu 11=Gonryun");
clif_displaymessage(fd, " 12=Umbala 13=Niflheim 14=Louyang");
clif_displaymessage(fd, " 15=Novice Grounds 16=Prison 17=Jawaii");
clif_displaymessage(fd, " 18=Ayothaya 19=Einbroch 20=Lighthalzen");
clif_displaymessage(fd, " 21=Einbech 22=Hugel 23=Rachel");
clif_displaymessage(fd, " 24=Veins 25=Moscovia 26=Mall");
return -1;
}
It's under atcommand_go