The filename iteration and data saving are executing in separate loops, I need to combine them.

Could someone indicate me how to combine the filename and data?

Thanks Bruno

for FileNum= 1 : length(files);

    filename=files(FileNum).name;

    filt1 = fdesign.highpass('n,f3db',4,2*10*(1/2000));

    H1 = design(filt1,'butter');

    Filter = filter(H1,data);

    save_data=fullfile(directory_save,filename);

    save(save_data,'Filter', '-ASCII');

end