Code:
Sub TF()
Dim rng As Range
Dim i As Long
Dim TF As Long 'Value 'Range
Set TF = Application.Match("TF", Sheets("Update").Range("1:1"), False) '.Value
With ActiveSheet
Set rng = .Range("A1:A" & .Cells(.Rows.Count, 1).End(xlUp).Row)
For i = 2 To rng.Rows.Count
rng.Cells(i, 4) = Application.WorksheetFunction.VLookup(.Cells(i, 1), Sheets("Update").Range("A:AZ"), TF, False)
Next
End With
End Sub