compare three workbooks with another workbook and create summary report

[abdo meghari]

hello
I have many files should copy all the data in theses files to file result the expected result highlighted the headers by red color
it should start from COL J to COL Y the data in sheet result are existed from COL A to I to match with the others files
when I match the data in sheet result should be COL B,C,D with the others files and the COL F with COL E in file REPORT1
and COL G with COL F in FILE REPORT2 and COL H with COL E in FILE REPORT2 and COL I with COL E in FILE STOCK after matching brings the values in COL J,K,,L,M after this should subtracting the values among the columns for instance in COLM N (STOCK1) should subtract COL I from COL J then if COL I more than COL J then the value should show in COL N(POSITIVE) and if less than COL J then the value should show in COL O(NEGETIVE) and mark wrong and if the value=0 it means no positive and no negative then mark right as in COL P (CASE1)
and the same thing for rests of columns P,Q,R,S,T,U,V,W,X,Y
should subtract and mark the right and wrong
note: may be there are some brands are existed in file stock and not found in file brands then should add to file result and show the values as in negative because they're not existed and I put some data in sheet result if it's not enough I will add more
finally if my explanation is not clear please tell me

[abdo meghari]

helps experts?