Trying to avoid updating a source document when executing a FOR loop

Hi guys,

I have been developing a Macro that does multiple VLOOKUPs depending en how many variables I want to search from other document. The source document may be variable, so I define it as a Variant (you will see it in the code)

Everything seems working fine although a little issue that actually pisses me off. When the for loop executes, excel constantly asks me to update the SourceFile document by opening a browser and it makes the macro useless. I don't know any solution for this incidence. Would anyone help me?

Thanks

Sub VLOOKUPs()

'Declare the variables
  Dim FilterIndex As Long
  Dim Title As String
  Dim SourceFile As Variant
  Dim n, counter, column As Integer
  Dim LR As Long

' Display *.* by default
  FilterIndex = 5
' Set the dialog box caption
  Title = "Select a File to Import"
' Get the filename
 SourceFile = Application.GetOpenFilename(, FilterIndex, Title)
' Handle return info from dialog box
  If SourceFile = False Then
    MsgBox "No file was selected."
  Else
    MsgBox "You selected " & SourceFile
  End If

'VLOOKUP
Range("A9").Activate
ActiveCell.FormulaR1C1 = "=VLOOKUP(RC2,'[(SourceFile)]Category data'!R1:R12000,R8C,FALSE)"

' Autofills the column depending on how many articles exists on the template
LR = Cells.Find(What:="*", SearchDirection:=xlPrevious, SearchOrder:=xlByRows).Row
Range("A9").AutoFill Destination:=Range("A9:A" & LR)

' Completes all the following columns
Range("A7").Select
n = Range(Selection, Selection.End(xlToRight)).Count
For counter = 7 To n
column = counter
Cells(9, column).Activate
ActiveCell.FormulaR1C1 = "=VLOOKUP(RC2,'[(SourceFile)]Category data'!R1:R14000,R8C,FALSE)"
Next

End Sub