Getting Process OutputStream without exec() it first

Hi there,
I am writing a java application which needs to open another application "gnuplot". Now my operating system is windows and I open pgnuplot .
Also I want to send input to the above gnuplot (say plot sin(x) ) via the outputStream. The following is what I do :-


String gnuplot_cmd = "plot sin(x)\n" ;
Process p = Runtime.getRuntime().exec("C:/gnuplot/gnuplot4/bin/pgnuplot.exe");

PrintWriter gp = new PrintWriter(p.getOutputStream());
gp.print(gnuplot_cmd);
gp.close();

But the above doesn't work fully , in that only the blank wgnuplot terminal window pops up however I am unable to direct input to the gnuplot application.

The reason being that , pgnuplot checks for
its stdin being redirected the moment it's started. If, at that time,
the "PrintWriter" is not yet connected to the OutputStream of the
process, that check will fail, and pgnuplot will revert to just executing
wgnuplot, without any command line redirection.

I am facing a problem of how to attach a OutputStream to the process, without getting exec()ing the process.
Is there anyway at all, i can get a process without starting it, so that I can attach an output Stream to it before it gets executed?
I am open to work arounds, anything that will automate the process of writing to the gnuplot terminal.

thanks!
nandita.