How to call a function with simple inputs in several MATLAB sessions automatically?
The manual way to do it would be:
You could try Multicore, which uses several instances of Matlab to do what parfor does by passing information via a common directory. If you can rewrite your code loop to call a function that returns values then Multicore might do what you are looking for.
http://www.mathworks.com/matlabcentral/fileexchange/13775-multicore-parallel-processing-on-multiple-cores