Not quite sure I understand what you are asking for.
But to remove parts of the meta refresh script (and known variations of it), simply go to...
AdminCP --> vBulletin Options --> Censorship Options --> Censored Words
And add these words and characters in the Censored Words window.
Code:
content=0 content="0 LANGUAGE= JavaScript Java {meta} {refresh} >> >>> >>>> >>>>> >>>>>>
My censorship options simply replace the words and characters with **** by default, but you can replace them with whatever you want.
That will stop the script and all known variations of it from being run.
*Note - I don't advise that you use this method if you run a computer related board that deals with code.