Something else to try:  Perl (Windows only) provides for this rarely used facility to set a custom command shell via the environment variable PERL5SHELL. In other words, on the command line that you're going to call your Perl program from, set that variable (prior to calling the program):

set PERL5SHELL=c:\\windows\\system32\\cmd.exe /c
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(yes, with doubled backslashes)

And maybe try something trivial first, e.g.

#!perl
system "echo foo >dummy";
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In theory, you should then find a file "dummy" with the content "foo".  In case that works, try your real command...