Data work in excel

I need data files combined in Excel format, and saved in date ranges. File formats to be combined are Excel or csv. Details: • Each group are categorized and will be combined within that category only – based upon date ranges. • Two files per month should be created of each category, file one for a month will include all files dated that month thru the 15th, and the 2nd file will include the last part of the month. o Example: March data for one category would derive two files: [login to view URL] and NODClark033109.xlsx. Categories of files, with quantities: NOD Clark 191 files from 3/19/09 to current (deliver 21 files total) NOS Clark 66 files from 9/23/09 to current (deliver 5 files total) Evelyn 82 files from 3/19/09 to 7/27/09 (deliver 9 files total) Sale 115 files to be saved by Date Modified – beginning 3/30/09 to 9/26/09 (deliver 13 files total)