Working with a combined workbook macro and need to add filename from each source book to Column 1

[ShadowSaxx]

Excel Ver. 2010

I have built a WB that combines the data from 50 or so WBs with a list of the files in Tab "List" and the data from each WB into Tab "Data"

I need to import the file name and write it into Column A. The only code I see is how to fill data that is already in the source sheet such in the code below. My file name is not in the data sheets I am combining so the code below does not work for that.

I am using a list of the files from the Tab "List"

Code from Live Lessons: Excel VBA and Macros with Mr Excel:

' Replicate the department from A2 to column A in WSD
WSD.Cells(NextRow, 1).Resize(RowCount, 1).Value = WSN.Range("A2")

Sub CombineFiles()
Dim WBO As Workbook ' original workbook
Dim WBN As Workbook ' individual data workbooks
Dim WSL As Worksheet ' List of files worksheet
Dim WSD As Worksheet ' data collection worksheet
Dim WSN As Worksheet

' Define object variables
Set WBO = ThisWorkbook
Set WSL = WBO.Worksheets("List")
Set WSD = WBO.Worksheets("Data")

Application.ScreenUpdating = False

' Clear out any previous data on WSD, but leave the headings
WSD.Cells(2, 1).Resize(Rows.Count - 1, Columns.Count).Clear

NextRow = 2

' Loop through all the files on WSL
FinalRow = WSL.Cells(Rows.Count, 1).End(xlUp).Row
For i = 1 To FinalRow
ThisFile = WSL.Cells(i, 1)
' Open a file
Set WBN = Workbooks.Open(Filename:=ThisFile)

For Each WSN In WBN.Worksheets

' Last row in this file? RowCount is 4 less <- Not Used Here use -1 to not grab headers.
LastRow = WSN.Cells(Rows.Count, 1).End(xlUp).Row
RowCount = LastRow - 1

' Copy from 5 to last row over to column B
WSN.Cells(2, 1).Resize(RowCount, 20).Copy Destination:=WSD.Cells(NextRow, 1)

-> ' Replicate the department from A2 to column A in WSD
-> ' WSD.Cells(NextRow, 1).Resize(RowCount, 1).Value = WSN.Range("A2")

' Set up the new NextRow
NextRow = NextRow + RowCount
Next WSN

' Close WSN, don't save
WBN.Close SaveChanges:=False

Next i

MsgBox "FILES HAVE BEEN PROCESSED"
Application.ScreenUpdating = True
End Sub

Thanks!
-SS