You make no sense.
Instead of asking for this specific thing (how to remove certain parts from a string), explain how all of this is set up. An RSS bot has come up in the discussion, and it sounds like you're running it, but that's all we really know. What RSS bot are we talking about here?
I will try to figure out what you are talking about:
You are running an RSS bot, which checks headlines from a news site's RSS feed, and when it runs, it messages to a certain channel the headlines, when a certain trigger is called on a channel. Now you want to edit the format in which it is messaged to the channel + you want it to send the headlines to another channel as well without retrieving the headlines again with a new trigger to the same news site, but with a different target channel. You want to avoid this, because the retrieving of the headlines is an intensive task and your slow computer has a hard time handling, and because it is simply stupid to check the headlines again if you already have them.
Does that sound somewhat like your situation? Well, I can't be sure of course, how could I with the information you've given...
All I can say is, this rss reader, if any good, should be storing the information somewhere (hashtable) when it checks for headlines, which means you don't have to retrieve them again, you can just grab them from the hashtable, and message them to your 2nd channel.
As far as changing the format, you'll need to edit the code so that it messages with that $gettok/$deltok applied on the lines to be sent.