You would be much better off using a macro, so that you
can make the changes in place, see
http://www.mvps.org/dmcritchie/excel/join.htm#trimall
where you can read about what you actually have, what the
CLEAN worksheet function actually does, and about copying
data from HTML sources.
What you are probably thinking of as illegal characters are
probably place holders in a font.
This question has been answered in the Excel newsgroups by
people like yourself (peer-to-peer) who volunteer their time to
answer questions. Most of those providing help are connecting
directly to the Microsoft newsservers and not using HTML based
access to newsgroups, which is much slower than using
Outlook Express or other newsgroup browsers.