So in the system NPC -
NPC Code:
if (playerchats) {
if (strequals(#c,/help)) {
triggeraction 0,0,serverside,"NPC-Control",help;
}
}
And System NPC -
NPC Code:
if (actionserverside) {
if (strequals(#p(0),help)) {
sendpm Pre-defined PM;
}
}
EDIT: Replacing "NPC-Control" with the correct NPC name