I understand that all file extensions (i.e. .php, .asp, .jsp...) caught by
HTTrack Website Copier are converted to .html
How would I force a .shtml instead of .html?(of course all the internal links
would also need to be .shtml...)

Failed alternatives:
1) I understand there is 'Set Options' / 'Build Structure' / 'User-Defined
Structure' and we could use something like "%r/%h%p/%n%.shtml" but this breaks
all other file type extensions
2) Using a script (i.e. Perl) to change all the file extensions and links
inside afterwards has it's exceptions and complications i.e. breaking outside
links... 
Where as it would be so much easier to be able to set .shtml instead of .html

Any tips, tricks, ideas, links and suggestions are much appreciated ;)

[I]Thank you all...[/I]