*EDIT* Just for clarification, I missed a word in my previous post... you do *NOT* want to accept messages with //decode or //write or $dll. And, you can probably choose to prevent other things as well depending what you want it to actually do.
For example, if you are just having it say messages to the channel, you could prevent all that start with / or // which would solve most those problems.
Example if statement:
if (/* iswm $3) {
.notice $2 Invalid text.
halt
}
