Text to n rows + copy row and insert n times

Sub undo()
With Worksheets("sheet2")
.Cells.Clear
End With
End Sub

Sub testthree120423()
Dim m As Long, j As Long, k As Long, semicolon() As Long
Dim n As Long, nname() As String
Dim r As Range, start As Long
Dim dest As Range
Dim r1 As Range
Dim length As Long
Application.ScreenUpdating = False
start = 1
undo
With Worksheets("sheet1")
j = .Range("a2").End(xlDown).Row
For k = 3 To j
Set r = .Cells(k, "L")
'MsgBox r.Address
With r
m = Len(r.Value) - Len(WorksheetFunction.Substitute(r, ";", ""))
'MsgBox m
ReDim nname(1 To m + 1)

If m = 0 Then
nname(1) = r.Value
GoTo m_is_zero
End If
End With
ReDim semicolon(1 To m)


'ReDim nname(1 To m + 1)
For n = 1 To m + 1
'msgbox n
If n = m + 1 Then
nname(n) = Mid(r, start, Len(r) - start + 1)
'msgbox nname(n)
GoTo nextstep
End If
'msgbox start
semicolon(n) = InStr(start, r, ";")
'msgbox semicolon(n)
length = semicolon(n) - start
'msgbox length
nname(n) = Mid(r, start, length)
'msgbox nname(n)
start = semicolon(n) + 1
'msgbox start
Next n
nextstep:
m_is_zero:
.Range(.Cells(k, 1), .Cells(k, "K")).Copy
With Worksheets("sheet2")
Set dest = .Cells(Rows.Count, "A").End(xlUp).Offset(1, 0)
Range(dest, dest.Offset(m, 0)).PasteSpecial
For n = 1 To m + 1
'dest.Offset(n - 1, 0).End(xlToRight).Offset(0, 1) = nname(n)
.Cells(dest.Offset(n - 1, 0).Row, "L") = nname(n)
Next n
End With
'Set r1 = Range(.Cells(k, "M"), .Cells(k, "M").End(xlToRight))

Set r1 = Range(.Cells(k, "M"), .Cells(k, Columns.Count).End(xlToLeft))
r1.Copy
With Worksheets("sheet2")
Set dest = .Cells(Rows.Count, "M").End(xlUp).Offset(1, 0)
Range(dest, dest.Offset(m, 0)).PasteSpecial
End With
start = 1
Next k
End With
With Worksheets("sheet2")
'Range(.Range("a2"), .Range("A2").End(xlDown)).EntireRow.AutoFit
'Range(.Range("A2"), .Range("a2").End(xlToRight)).EntireColumn.AutoFit

Range(.Range("a2"), .Cells(Rows.Count, "A").End(xlUp)).EntireRow.AutoFit
Range(.Range("A2"), .Cells(2, Columns.Count).End(xlToLeft)).EntireColumn.AutoFit

End With
Application.ScreenUpdating = True
Application.CutCopyMode = False
MsgBox "macro over"
End Sub