Compare excel two sheets duplicate value

I need help for excel two sheets compare and find duplicate value and mark ‘Dup’ in another column.
1) Sheet1 having two columns as Col1-EmpCode and Col2 PFCode.(No duplicate records in this sheet)
2) Sheet2 having 5 columns as Col1-EmpCode, Col2-Name, Col3-Designation, Col4-PFCode, Col5-Remarks (More than 10000 records with duplicate Empcode and PFCode)
I need to compare Sheet1 Col1 , Col2 with Sheet2 Col4 and find match “Dup” in sheet2 Col5-Remarks.
I NEED EXCEL VBA with fast finding.Please help