Thread Subject: Using the system command to launch a multi-threaded PC executable

I have a Windows executable file that runs stochastic simulations as separate threads and then averages the results together at the end.

I would like to run the simulations from MATLAB using the system command. Everything works fine if I run the 4-threaded version of the executable but the executable returns early (without reporting an error) if I try to run 5 or more threads.

I suspect that this is because my Windows 7 machine has 4 cores and maxNumCompThreads (see http://www.mathworks.com/help/techdoc/ref/maxnumcompthreads.html) is therefore equal to 4.

Is there a way of successfully launching the 6-threaded version of the executable from MATLAB (2011a - or b if it makes a difference) ?

Thanks in advance for any help,

Ken