Remove question marks and convert illegal characters when renaming from tags

Hello, I am a new user to MP3tag, but I must say I really like it. Here is my problem or what I want to do. It's about tag to filename converter. I would like to eliminate question marks and convert all other illegal characters to a dash. That's it! I would use $validate, except I don't want dashes in my filenames where there are ? in my tags. How can I replace ? with nothing and then replace all other illegal chars with just a dash?
Thanks in advance, Tom.

you could use nested scripting functions:
$validate($replace(%my_field_list%,?),-)
the $replace() takes care of the ? and $validate() takes care of all the other characters.
And while you are at it: perhaps you want to replace the / and \ as well - as this sometimes leads to the unexpected creation of sub-directories but as these are valid characters for paths, they do not get caught by $validate().
So:
$validate($replace(%my_field_list%,?,/,\,),-)