extracting the the first n columns of X and Y

I nedd to extract only the first n columns of a data I loaded into my function and have to enforce n<=9 and also use a loop to plot the rth column of X against the rth column of Y in the rth subplot, I am allowed to choose how many subplots I want, I really need help with this, right now ive figured out,

function coa08xxx_lines(n)

        s = load('xydata.mat','X','Y');

        theTable = s.theTable;

        [rows, columns] = size(theTable);
        columnsToExtract = [];

for c = 1 : n : (columns-n)

columnsToExtract = [];
end

[Walter Roberson]

Where is your code for choosing the number of subplots that you want?

[Chris]

i dont know how to do that, was hoping someone could explain this to me, let's say my value of r is 1,2 and 3. do you know what im supposed to type in?