s = '\\198.168.0.10\share\ccdfiles\UA-midd3-files\UA0001A_15_Jun_2014_08.17.49\Midd3\y12m05d25h03m16.midd3';
res = regexp(s, '(?i)\\(?![^\W_]*(midd|y\d+m\d+))(?=[^\W_]*\d)(?=[^\W_]*[a-zA-Z])([^\W_]+)','tokens');
disp(res{1}{1})
cyA9ICdcXDE5OC4xNjguMC4xMFxzaGFyZVxjY2RmaWxlc1xVQS1taWRkMy1maWxlc1xVQTAwMDFBXzE1X0p1bl8yMDE0XzA4LjE3LjQ5XE1pZGQzXHkxMm0wNWQyNWgwM20xNi5taWRkMyc7CnJlcyA9IHJlZ2V4cChzLCAnKD9pKVxcKD8hW15cV19dKihtaWRkfHlcZCttXGQrKSkoPz1bXlxXX10qXGQpKD89W15cV19dKlthLXpBLVpdKShbXlxXX10rKScsJ3Rva2VucycpOwpkaXNwKHJlc3sxfXsxfSkK