This code should do it
function serverCmdLe(%client, %n1, %n2, %n3, %n4, %n5, %n6) {
if (!%client.isAdmin)
return;
%name = trim(%n1 SPC %n2 SPC %n3 SPC %n4 SPC %n5 SPC %n6);
if (isObject(%target = findClientByName(%name)))
%target.isLe = !%target.isLe;
}
package LePackage{
function serverCmdMessageSent(%client, %text) {
if (%client.isLe) {
%wordCnt = getWordCount(%text);
for (%i = 0; %i < %wordCnt; %i++) {
%word = getWord(%text, %i);
if (strLwr(%word) $= "the") {
// Account for different capitalization
// Probably a better way to handle this, but whatever
if (%word $= "the")
setWord(%text, %i, "le");
else if (%word $= "The")
setWord(%text, %i, "Le");
else if (%word $= "THE")
setWord(%text, %i, "LE");
else
setWord(%text, %i, "lE");
}
}
}
Parent::serverCmdMessageSent(%client, %text);
}
};
activatePackage(LePackage);
I'll test it quick and package up an add-on for you.