This macro converts successful VLOOKUP formulas into values (thereby "locking" them) in case your lookup table has to change

convert_lookups_to_values.vb

Option Explicit
Public Sub ConvertLookupsToValues()

    Dim lngLastRow As Long, lngIdx As Long
    Dim varLookups As Variant
    
    'Everything happens on the Ledger sheet
    With ThisWorkbook.Worksheets("Ledger")
    
        'Identify the last-occupied row in column D on the Ledger sheet,
        'then store all the values in a column array (variant type)
        lngLastRow = .Cells(.Rows.Count, 4).End(xlUp).Row
        varLookups = .Range(.Cells(3, 4), .Cells(lngLastRow, 4))
        
        'Loop through the array, writing values over the existing
        'formulas if the lookup was successful
        For lngIdx = 1 To UBound(varLookups)
            If varLookups(lngIdx, 1) <> 0 Then
                .Cells(2 + lngIdx, 4) = varLookups(lngIdx, 1)
            End If
        Next lngIdx
        
    End With

End Sub