Help with RegExps

[Chris...]

Dear RegExp-Gurus...

  I am looking for an regular expression that changes text, only if it
is not anywhere between '<' and '>'.
For example, add syntax highlighting to HTML-file:
    'some text <a href=#someRef>ref</a> # this is a comment'
should be changed to
    'some text <a href=#someRef>ref</a> <font color=blue># this is a
comment</font>'

  Is this possible with python's re module?

  Thanks a lot in advance!!!

bye
  Chris...