Cycling through folders and changing excel files within each folder

Hi,

I am using individual excel files in separate folders to store inspection plans for thousands of parts. I have created close to 3,000 excel files, and now I am told I need to change the header and footer, or else we may get dinged in an audit. I need a way to cycle through each folder (which we will call MOLD#) in a main folder (which we will call Q), and open every excel file in the folder called INSPECTION PLAN, and change the footer/header.

Q
~~MOLD#1
~~~~INSPECTION PLAN
~~~~~~Excel file1 <------ need to change this
~~MOLD#2
~~~~INSPECTION PLAN
~~~~~~Excel file1 <------ need to change this
~~~~~~Excel file2 <------ need to change this
etc....

Also to complicate things, the folder INSPECTION PLAN may or may not exist. If it doesn't exist, then it should just skip to the next MOLD#.

I can take care of the rest of the programming, I just cannot seem to find a program to do the folder cycling I am looking for. Any help will be much appreciated.

Thank you so much kev!

I took the code you provided and I am now able to cycle through my folders. I had to amend it to go one folder deeper, as the files I need to amend would be 2 subfolders down from the host folder. Also the mold# and inspection plan.xlsx file names vary, so I took out the if statements.

Sub LoopFolders()
    Dim FileSystem As Object, HostFolder As String
    HostFolder = "Q:\Mold"

    Set FileSystem = CreateObject("Scripting.FileSystemObject")
    DoFolder FileSystem.GetFolder(HostFolder)
End Sub

Sub DoFolder(Folder)
    Dim SubFolder, SubSubFolder, File, wb As Workbook
    
    For Each SubFolder In Folder.SubFolders
        For Each SubSubFolder In SubFolder.SubFolders
            If SubSubFolder.Name = "Inspection Plan" Then
                For Each File In SubSubFolder.Files
                    Set wb = Workbooks.Open(SubSubFolder & "\" & File.Name)
                        'do changes here'
                    wb.Close
                Next File
            End If
        Next SubSubFolder
    Next SubFolder
End Sub