The new LimeWire 4.3.2 Beta version has brought back the Annotate button which will allow you to change the name of the file (or delete that illegal character) whilst you are downloading it. The description is here: http://www.gnutellaforums.com/showth...threadid=32416
Get Beta here: http://www.limewire.com/english/content/beta.shtml

If you are a Limewire Pro user you will find the link to the Beta at the bottom of your personal download page.