Making range delete code more efficient

Hello everyone,

I would appreciate some help with making the following code more efficient (got it online). It works as it is but I have two issues with it that I can't seem to solve:



1) I can't seem to be able to replace this code

.Value = "2014-09-05_2014-10-03"

with something more flexible like the following. Am I doing something wrong or is it the way the macro is made that prevents this change?

.Value = .Range("A1")

2) I read that structuring a range reference in the following way was "frowned upon." Why is that and how do I improve this?

Range("M" & Lrow & ":" & "P" & Lrow)

If there is anything else you see that can improve the code, please let me know. The entire code is below.

Sub Loop_Example()
    Dim Firstrow As Long
    Dim Lastrow As Long
    Dim Lrow As Long
    
   


        With Worksheets("ref")

        'Set the first and last row to loop through
        Firstrow = 2
        Lastrow = .Cells(.Rows.Count, "P").End(xlUp).Row


        'We loop from Lastrow to Firstrow (bottom to top)
        For Lrow = Lastrow To Firstrow Step -1

            'We check the values in the P column in this example
            With .Cells(Lrow, "P")

                If Not IsError(.Value) Then

                    If .Value = "2014-09-05_2014-10-03" Then Range("M" & Lrow & ":" & "P" & Lrow).Delete (xlShiftUp)
                    'This will delete cells in the M:P column range where at lrow, .Value is the same as above
                    'in Column P, case sensitive.

                End If

            End With

        Next Lrow

    End With

    

End Sub

Thanks!

Geoff.