"cmd /c" has limitation when using double quote(")
Put a \ in front of each " which you wish to preserve.

i don't know the perl function to get path of cmd.exe since using "set comspec" also shows its output in DOS Window.
Comspec is an environment variable, so in Perl use $ENV{Comspec}

By the way, the pedant in me must point out that the correct term is "Console", not "DOS", window (assuming you are not using 16-bit DOS, of course).