VBA macro that search for file in multiple subfolders

Just for fun, here's a sample with a recursive function which (I hope) should be a bit simpler to understand and to use with your code:

Function Recurse(sPath As String) As String

    Dim FSO As New FileSystemObject
    Dim myFolder As Folder
    Dim mySubFolder As Folder

    Set myFolder = FSO.GetFolder(sPath)
    For Each mySubFolder In myFolder.SubFolders
        Call TestSub(mySubFolder.Path)
        Recurse = Recurse(mySubFolder.Path)
    Next

End Function

Sub TestR()

    Call Recurse("D:\Projets\")

End Sub

Sub TestSub(ByVal s As String)

    Debug.Print s

End Sub

Edit: Here's how you can implement this code in your workbook to achieve your objective.

Sub TestSub(ByVal s As String)

    Dim FSO As New FileSystemObject
    Dim myFolder As Folder
    Dim myFile As File

    Set myFolder = FSO.GetFolder(s)
    For Each myFile In myFolder.Files
        If myFile.Name = Range("E1").Value Then
            Debug.Print myFile.Name 'Or do whatever you want with the file
        End If
    Next

End Sub

Here, I just debug the name of the found file, the rest is up to you. ;)

Of course, some would say it's a bit clumsy to call twice the FileSystemObject so you could simply write your code like this (depends on wether you want to compartmentalize or not):

Function Recurse(sPath As String) As String

    Dim FSO As New FileSystemObject
    Dim myFolder As Folder
    Dim mySubFolder As Folder
    Dim myFile As File

    Set myFolder = FSO.GetFolder(sPath)

    For Each mySubFolder In myFolder.SubFolders
        For Each myFile In mySubFolder.Files
            If myFile.Name = Range("E1").Value Then
                Debug.Print myFile.Name & " in " & myFile.Path 'Or do whatever you want with the file
                Exit For
            End If
        Next
        Recurse = Recurse(mySubFolder.Path)
    Next

End Function

Sub TestR()

    Call Recurse("D:\Projets\")

End Sub

This sub will populate a Collection with all files matching the filename or pattern you pass in.

Sub GetFiles(StartFolder As String, Pattern As String, _
             DoSubfolders As Boolean, ByRef colFiles As Collection)

    Dim f As String, sf As String, subF As New Collection, s
    
    If Right(StartFolder, 1) <> "\" Then StartFolder = StartFolder & "\"
    
    f = Dir(StartFolder & Pattern)
    Do While Len(f) > 0
        colFiles.Add StartFolder & f
        f = Dir()
    Loop
    
    If DoSubfolders then
        sf = Dir(StartFolder, vbDirectory)
        Do While Len(sf) > 0
            If sf <> "." And sf <> ".." Then
                If (GetAttr(StartFolder & sf) And vbDirectory) <> 0 Then
                        subF.Add StartFolder & sf
                End If
            End If
            sf = Dir()
        Loop
    
        For Each s In subF
            GetFiles CStr(s), Pattern, True, colFiles
        Next s
    End If

End Sub

Usage:

Dim colFiles As New Collection

GetFiles "C:\Users\Marek\Desktop\Makro\", FName & ".xls", True, colFiles
If colFiles.Count > 0 Then
    'work with found files
End If

If this helps, you can also use FileSystemObject to retrieve all subfolders of a folder. You need to check the reference "Microsot Scripting Runtime" to get Intellisense and use the "new" keyword.

Sub GetSubFolders()

    Dim fso As New FileSystemObject
    Dim f As Folder, sf As Folder

    Set f = fso.GetFolder("D:\Proj\")
    For Each sf In f.SubFolders
        'Code inside
    Next

End Sub