Making Changes in a Group of Workbooks

Over time, it is very easy to create and collect a huge number of Excel workbooks. Suppose that you had a whole bunch of workbooks in which you needed to make the same change. For instance, you might need to change the value stored in cell A10 of each of the worksheets in each of the workbooks.

If you had only a few workbooks to change, the task is pretty easy: Load each workbook and, in turn, make the change to each of them. If you have a couple hundred workbooks in which the change needs to be made, then the task becomes more formidable.

If you anticipate only needing to do this task once, then the easiest solution is to create a text file that contains the path and filename of each of the workbooks, one workbook per line. For instance, you might end up with a file that had entries such as this:

c:\myfiles\first workbook.xls
c:\myfiles\second workbook.xls
c:\myfiles\third workbook.xls

The file could have as many lines in it as necessary; it doesn't really matter. The important thing is that each line be a valid path and file name, and that there be no blank lines in the file.

You could most easily create such a file by displaying a command-prompt window, navigating to the directory containing the workbooks, and issuing the following command:

dir /b >myfilelist.txt

Each file in the directory ends up in the myfilelist.txt file. You will need to load the text file into a text editor and check it out so you can delete extraneous entries. (For instance, myfilelist.txt will end up in the listing.) You will also need to add the path name to the beginning of each line in the file.

Once the file is complete, you can start Excel and use a macro to read the text file, load each workbook listed in the text file, step through each worksheet in that workbook, make the appropriate change, and save the workbook. The following macro will perform these tasks nicely.

Sub ChangeFiles1()
    Dim sFilename As String
    Dim wks As Worksheet

    Open "c:\myfiles\myfilelist.txt" For Input As #1
    Do While Not EOF(1)
        Input #1, sFilename  ' Get workbook path and name
        Workbooks.Open sFilename

        With ActiveWorkbook
            For Each wks In .Worksheets
                ' Specify the change to make
                wks.Range("A1").Value = "A1 Changed"
            Next
        End With

        ActiveWorkbook.Close SaveChanges:=True
    Loop
    Close #1
End Sub

While this approach works great if you only have to process a single batch of workbook files, it can be made much more flexible if you anticipate needing to make such changes in the future. The biggest hassle, of course, is putting together the myfilelist.txt file each time you want to process a batch of files. Flexibility is added if the macro could simply use a directory and then load each workbook from that directory.

Sub ChangeFiles2()
    Dim MyPath As String
    Dim MyFile As String
    Dim dirName As String
    Dim wks As Worksheet

    ' Change directory path as desired
    dirName = "c:\myfiles\"

    MyPath = dirName & "*.xls"
    MyFile = Dir(MyPath)
    If MyFile > "" Then MyFile = dirName & MyFile

    Do While MyFile <> ""
        If Len(MyFile) = 0 Then Exit Do 

        Workbooks.Open MyFile

        With ActiveWorkbook
            For Each wks In .Worksheets
                ' Specify the change to make
                wks.Range("A1").Value = "A1 Changed"
            Next
        End With

        ActiveWorkbook.Close SaveChanges:=True

        MyFile = Dir
        If MyFile > "" Then MyFile = dirName & MyFile
    Loop
End Sub 

This macro uses whatever directory you specify for the dirName variable. Any workbook file (ending with the .Xls extension) is loaded and processed.

Another approach is to have the macro ask the user which directory should be processed. You ca use the standard Excel File dialog box to do this, in the manner shown in the following macro.

Public Sub ChangeFiles3()
    Dim MyPath As String
    Dim MyFile As String
    Dim dirName As String

    With Application.FileDialog(msoFileDialogFolderPicker)
        ' Optional: set folder to start in
        .InitialFileName = "C:\Excel\"
        .Title = "Select the folder to process"
        If .Show = True Then
            dirName = .SelectedItems(1)
        End If
    End With

    MyPath = dirName & "\*.xls"
    myFile = Dir(MyPath)
    If MyFile > "" Then MyFile = dirName & MyFile

    Do While MyFile <> ""
        If Len(MyFile) = 0 Then Exit Do 

        Workbooks.Open MyFile

        With ActiveWorkbook
            For Each wks In .Worksheets
                ' Specify the change to make
                wks.Range("A1").Value = "A1 Changed"
            Next
        End With

        ActiveWorkbook.Close SaveChanges:=True

        MyFile = Dir
        If MyFile > "" Then MyFile = dirName & MyFile
    Loop
End Sub