good news:
Ghisler added support for passing archives to SI in TC7.5 Beta8

in history.txt:
"21.07.09 Added: Button bar, start menu: New parameter %Z: Allow to pass name of archive in %P or %T parameter (only recommended if the called program can handle it)"
and in the help file:
"%Z anywhere in the parameters: Allow to pass archives as path to programs for %P or %T when inside an archive
Example: %Z%P passes name of archive to external tool when TC shows contents of an archive"
Bad news:
I cannot get it to work.

Could you try and let us know if you succeed?
Please use long file- and pathnames with spaces in your trials.
Regards,
Brahman