system takes a command as its first argument and the command-line arguments to that command as its next arguments. Well, it might not be that clear... Here an example:

system("SQL", "<", "calfile.txt");
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Now, I don't know too much how MSDOS parses its command-line, but if it is like a Unix-shell, I/O redirections are not part of the command-line. Which means that the code above won't work.

If SQL accepts to have commands piped into it, you can try something like:

open IN, "<calfile.txt" or die "Aaargh: $!\n";
open OUT, "|SQL" or die "Ooops: $!\n";
print OUT, <IN>;
close OUT;
close IN;
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And what is this double percent sign, and where are you trying to use it? On MSDOS command-line, in system,...?

HTH
--bwana147