//...
static struct TS3Functions ts3libfuncs;
//...

void ts3plugin_setFunctionPointers(const struct TS3Functions functions) {
  ts3libfuncs = functions;
}

//...

int ts3plugin_onTextMessageEvent(uint64 schid, anyID targetMode, anyID toID, anyID fromID, const char* fromName, const char* fromUniqueIdentifier, const char* message, int ffIgnored) {
  uint64 curschid;
  if (ts3libfuncs.getCurrentServerConnectionHandlerID(&curschid) != ERROR_ok) {
    //oops, something went wrong getting the current schid, but we are too lazy to get an error message with ts3lib.getErrorMessage(err, ...)
    return 0;
  }

  if (curschid != schid)
    return 0;

  if (targetMode != TextMessageTarget_CLIENT) {
    //react only on private messages
    return 0;
  }

  if (!strcmp(message, "!banme")) {
    unsigned int err = ts3libfuncs.banclient(schid, fromID, 1000, "Who wants to be banned, gets banned", NULL);
  }

  return 0; //the client will show the textmessage as normal
}