another easy way would be make use of these
addrid + dispbottom
https://github.com/rathena/rathena/blob/master/doc/script_commands.txt#L3770-L3788
or areaannounce
*areaannounce "<map name>",<x1>,<y1>,<x2>,<y2>,"<text>",<flag>{,<fontColor>{,<fontType>{,<fontSize>{,<fontAlign>{,<fontY>}}}}}};
This command works like 'announce' but will only broadcast to characters
residing in the specified x1/y1-x2/y2 rectangle on the map given. The
flags and optional parameters are the same as in 'announce', but target
and source flags are ignored.
areaannounce "prt_church",0,0,350,350,"God's in his heaven, all right with the world",0;