sourcefolder = 'C:\some\folder';
destinationfolder = 'C:\some\other\folder';
[score, M] = xlsread(fullfile(sourcefolder, filename));
%...
xlswrite(fullfile(destinationfolder, outputdatafilename), filterdata);
sourcefolder = 'C:\some\folder';
fcontent = dir(fullfile(sourcefolder, '*.xlsx')); %fcontent is a column vector of structures
for file = fcontent'
filename = file.name;
[score, M] = xlsread(fullfile(sourcefolder, filename));
%...
end
[~, outputfilename] = fileparts(filename);
outputdatafilename = sprintf('output_%s.xlsx' outputfilename);
Although in your case, I don't understand why you're removing the '.xlsx' only to add it back on the next line, so you might as well simply do:
outputdatafilename = ['output_' filename];
