I have created a macro code to formate my excel file below is the code

sub test()
ChDir "C:\N"
Workbooks.Open Filename:="C:\N\AU.xls"
Rows("1:1").Select
With Selection.Interior
.ColorIndex = 6
.Pattern = xlSolid
End With
End sub

The above code work only in file AU.xls, i would like to have a short macro
code to open my other three files (BU.xls, DU.xls, EF.xls) and perform the
same action to it.

Is it possible to put the formate part in loop.