Don`t censore the "Subject" part

[J. S.]

Is that possible? If I am adding a censored word that I want to make a link, I`ll get a

Koodi [Valitse] Laajenna

[url=http://blah.com]blah[/url] in the "Subject" field.

So.. what I want it to make "blah" a link only in post, not in the "subject" field..