The following expression returns a category string in relation to the first letter of the filename, adapt it to your needs. $ifgreater($strchr('0123456789',$left(%_FILENAME%,1)),0,'0 - 9',$ifgreater($strchr('ABCDEabcde',$left(%_FILENAME%,1)),0,'A - E',$ifgreater($strchr('FGHIJKfghijk',$left(%_FILENAME%,1)),0,'F - K',$ifgreater($strchr('LMNOPQRlmnopqr',$left(%_FILENAME%,1)),0,'L - R',$ifgreater($strchr('STUVWXYZstuvwxyz',$left(%_FILENAME%,1)),0,'S - Z','Special')))))
DD.20071228.1439.CET