Insert rows after every new reference shows up in a column - excel

Question

I have data in a column and I am trying to run a macro so that a new row (a preset line) is inserted every time a new value is found.
Here is an example of how the data looks currently:
1 C 100
1 D 100
1 E 100
1 F 100
1 G 100
2 C 200
2 D 200
2 E 200
I want the macro to look in the first column and if there is a new value then insert a row (paste a predefined line)
This is the outcome:
1 C 100
1 D 100
1 E 100
1 F 100
1 G 100
Predefined line copied
2 C 200
2 D 200
2 E 200
Predefined line copied
My current code looks like this. It is not working:
Sub InsertCreditorLine()
'based on value in column AB, works out where new expense starts and inserts the creditor line formula row
Dim Col As Variant
Dim BlankRows As Long
Dim LastRow As Long
Dim PrintArea1 As Variant
Dim R As Long
Dim StartRow As Long
' works out last row to work up from
Col = "AB"
StartRow = 6
BlankRows = 1
LastRow = Cells(Rows.Count, Col).End(xlUp).Row
Application.ScreenUpdating = False
With ActiveSheet
For R = LastRow To StartRow + 1 Step -1
'Looks to value in column AB to see where new expense starts
If .Cells(R, Col) = "Y" Then
'paste in line
Rows("1:13").Select
Selection.EntireRow.Hidden = False
.Cells(7, 7).EntireRow.Copy
.Cells(R, Col).EntireRow.Insert Shift:=xlDown
End If
Next R
End With
Application.CutCopyMode = False

Answer 1

How about this?
Sub InsertCreditorLine()
Dim startRow As Long, lastRow As Long, presetRow As Range, rw As Long
startRow = 6
lastRow = Range("AB" & Rows.Count).End(xlUp).Row
Set presetRow = Range("7:7")
For rw = lastRow To startRow + 1 Step -1
If Range("AB" & rw) <> Range("AB" & rw).Offset(-1, 0) Then
presetRow.Copy
Range("AB" & rw).Insert Shift:=xlDown
End If
Next rw
End Sub