Elijah - try using xlsread to get the 200th element of the second column. If you have a list of *.xlsx files, then as you iterate through this list, just read the single element from each file and store it in an array
x(k) = xlsread(myFilename,'B200');
myFilename is just a local variable representing the kth filename (say, 'myFileK.xlsx'). You may need to supply the worksheet name before the 'B200' string. See the xlsread documentation for details.
