> Is there an option keep original non-converted names
> and later convert/export them to be burnt ?
No, not really. A workaround would be to mirror the "local 
site" ; by starting a fresh project whose starting URL 
would be something like 
<file://C:\existing_mirror\index.html> (create a new project, 
and draw&drop the top index.html in httrack), and of course 
select the "iso9660" option (warning: bogus option up to 
3.33RC2)