collection monthly report for multiple files into one

hi experts !
I have report publish every month throught the year. what i want collect the all of the files into one . so the result in file collection shows each sheet for each file and rename for each sheet based on file name because all of the sheets names are the same in all of the files . the location of columns are different in orginal file so I want to arrange location of the columns as in file collection . after this should create the sheet is name YEAR , then should combined the data of all sheets into one sheet YEAR and summing the values for duplicates items for columns sales & returns.
note I want create the file every time when run the macro in the same folder contains the files .
thanks