Help me implement SPMD

I have wrote the following random walk script that works well:

clear all; close all; clc;
N = [1:100];
XX = zeros(1,10);
X = randi(10,1);
R = zeros(1,100);
for i = 1:length(R)
    R(i) = randi(2,1);
    if R(i) == 1
        X = X + 1;
        if X == 11
            X = 1;
        end
    elseif R(i) == 2
        X = X - 1;
        if X == 0
            X = 10;
        end        
    end
    XX(i) = X;
end
scatter(N,XX,'.')

Now, I would like to implement spmd, using two cores, where lab 1 takes care of grid 1:5 and lab 2 takes care of grid 6:10.

I have used spmd previously, but I am having a difficult time implenting it into my criteria. I would appreciate any help, advice, examples to get me started.