According to the source (win32.c), COMSPEC isn't called ...
in reply to Re: system command erroneously states 'can't spawn <executable>'
in thread system command erroneously states 'can't spawn <executable>'
I don't really understand the second point ...
/* we don't use COMSPEC here for two reasons:
* 1. the same reason perl on UNIX doesn't use SHELL--rampant and
* uncontrolled unportability of the ensuing scripts.
* 2. PERL5SHELL could be set to a shell that may not be fit for
* interactive use (which is what most programs look in COMSPE