Managing directories and log file names

Fixed a issue where the batch was looking for unexistant log files (wrong name format inherited from the old %dtl% var, now %dtyl%, properly formatted to match previously log file name format.) and additionally checks for the monthly backup log folder at C:\ instead of trying to create the folder whether there were already a folder or not (same practical result, except that now it won't throw errors since it checks for a pre-existing folder.).