Supprimer Ligne avec condition

Option Explicit
Sub Ligne_supprimer_selon()
    Dim c As Range, i As Long
    With Application: .ScreenUpdating = False: .Calculation = xlManual: .EnableEvents = False: End With
    For i = Cells(Rows.Count, "a").End(xlUp).Row To 2 Step -1
        If Left(Range("a" & i), 1) = "R" Or IsNumeric(Range("a" & i)) Then Rows(i).Delete
    Next
    With Application: .EnableEvents = True: .Calculation = xlAutomatic: .ScreenUpdating = True: End With
End Sub

Sub Test()
LignesOùCondR1C1(Rows(2), "UPPER(LEFT(RC1,1))=""R""").Delete
LignesOùCondR1C1(Rows(2), "EXACT(UPPER(LEFT(RC1,1)),LOWER(LEFT(RC1,1)))").Delete
End Sub

Function LignesOùCondR1C1(ByVal LigneDéb As Range, ByVal CondR1C1 As String) As Range
Rem. ——— Lignes entières partant de LigneDéb qui vérifient une condition R1C1 CondR1C1.
Dim Lignes As Range, ColTrv As Range
With LigneDéb.Worksheet.UsedRange
   Set Lignes = LigneDéb.EntireRow.Resize(.Rows.Count + .Row - LigneDéb.Row)
   Set ColTrv = Intersect(.Columns(.Columns.Count + 1), Lignes): End With
ColTrv.FormulaR1C1 = "=1/(" & CondR1C1 & ")"
On Error Resume Next
Set LignesOùCondR1C1 = ColTrv.SpecialCells(xlCellTypeFormulas, 1).EntireRow
ColTrv.Delete xlShiftToLeft
End Function