This should work (tested)
Sub test()
    Dim x, e, r As Range, t As Long, wbName As String
    Const myDir = "C:\sample\Master Data\"   '<--- folder path
    Const fn As String = "master data jun'20.xlsx"  '<--- workbook.name
    Const ws As String = "Loader"   '<--- worksheet name
    Application.ScreenUpdating = False
    wbName = "'" & myDir & "[" & Replace(fn, "'", "''") & "]" & ws & "'!": t = 1
    For Each e In Array(1, 2, 12, 13, 17)
        t = t + 1
        Cells(5, t) = ExecuteExcel4Macro(wbName & "r16c" & e)
    Next
    For Each r In Range("b6", Range("b" & Rows.Count).End(xlUp))
        r(, 3).FormulaArray = "=match(""" & r.Value & """&""" & r(, 2).Value & """," & _
                                wbName & "a1:a100000&" & wbName & "b1:b100000,0)"
        x = r(, 3): r(, 3).Resize(, 3).ClearContents: t = 2
        If Not IsError(x) Then
            For Each e In Array("L", "M", "Q")
                t = t + 1
                r(, t).Formula = "=" & wbName & e & x
            Next
            r(, 3).Resize(, 3).Value = r(, 3).Resize(, 3).Value
        End If
    Next
    Application.ScreenUpdating = True
End Sub