Problem using exec() from Java servlet

I have been struggling with a problem for the past couple of days, and
am looking for any help that can be offered.

I have a servlet that I need to access a file in my companies version
manager software. The tomcat server is running on my machine, but when
it tries to execute the command line argument, I am getting the
following error:

java.io.IOException: CreateProcess: pcli -h error=5

Note that this error ONLY occurs when executing from a servlet. If I
just run it in Eclipse, for example, it runs fine.

In the end I obvioisly want to be doing something a bit more complex
than that but here, I am trying to run the help command on pcli.exe.
That executable is on a different machine than the server, but I have
set all necessary system properties prior to executing the command.
Here is my code:

//Set system properts
.....
System.setProperty("Path","directory containin pcli.exe");

//Run command
Runtime.getRuntime().exec("pcli -h");


I don't feel like doing this should be so complex, but I can't seem to
find the problem. Could it be a server security issue? ANY
suggestions offered will be greatly appreciated.

.