This part:

        else {
            $call = <Something I make here>;  # sorry, can't show that
            open (OUT, "| $call");
            close (OUT);
            exit;
        }
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can be simplified to

        else {
            $call = <Something I make here>;  # sorry, can't show that
            exec $call || die "Something went wrong!";
        }
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But you should better consider using @call, putting each option and parameter of the call into it's own @call element and using the complete path for the first parameter, the program's name.
For example instead of

$call= "myperlscript -param1 $var1 -param2 $var2";
exec $call;
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use something like this:

@call= ('/my/home/dir/myperlscript','-param1',$var1,'-param2',$var2);
exec @call;
[download]