Not sure you really want to remove every cases of special characters.
Anyway, this is how to remove all special characters except a comma, a dot, and a space from title:
$RxReplace(<Title>,"[^a-zA-Z0-9,. ]","")
To remove them from filename, replace <Title> with your entire "filename" template (e.g. <Track#> <Artist> <Title>) after adjusting the character exceptions in the code.