Hey,
I'm really stuck on this. I'm trying to use regexp twice once for all the files i need to work with and then again to narrow it down even more.
textfiles = dir('*.txt');
filenames = {textfiles.name};
filenames = regexp(filenames, '^sn\d{4}_INS_(LOW|HIGH)_\d+_\d+_(A|B).txt$', 'match')...