Emunge

[donald]

Emunge is an application for filtering text.

Emunge will perform a series of regular expression search and replace operations with text from the clipboard or entered into the program's left window pane, the output text displays in the right window pane.

This application is .NET so vote accordingly

[webfork]

There's a short howto on the homepage that is probably necessary to getting started: http://keir.net/emunge.html