using data in ws1, append data in ws2 only if data is different, otherwise overwrite

[anoubis450]

I was hoping someone might be able to help me out with this. I have included the code that I am currently working with. This allows me to transfer a range of data from ws1(Current Performance) to ws2(Past Monthly Performance) and it appends to the next blank row; however, I would like for it to overwrite the existing data based on a condition otherwise it should append it to the next blank row.

For example, C3 on ws1 shows May 2017. If ws2 has a section that shows May 2017, then I need that range overwritten; otherwise, the new data should append to the existing data.

Any assistance would be greatly appreciated.

Sub CopyAllData()
   'update these Const values for Worksheet 1

   Const ws1Name = "Current Performance"
   Const firstRowToCopy = 3
   Const alwaysUsedCol = "C"
   Const firstColToCopy = "C"
   Const lastColToCopy = "I"

   Const ws2Name = "Past Monthly Performance"
   
   'end of user definable Const values
   
   Dim ws1 As Worksheet
   Dim ws1LastRow As Long
   Dim ws1CopyRange As Range
   Dim ws2 As Worksheet
   Dim ws2NextRow As Long

   Set ws1 = Worksheets(ws1Name)
   Set ws2 = Worksheets(ws2Name)
   ws1LastRow = ws1.Range(alwaysUsedCol & Rows.Count).End(xlUp).Row
   If ws1LastRow < firstRowToCopy Then
     ws1LastRow = firstRowToCopy
   End If
   
   Set ws1CopyRange = ws1.Range(firstColToCopy & firstRowToCopy & _
    ":" & lastColToCopy & ws1LastRow)
   ws2NextRow = ws2.Range(alwaysUsedCol & Rows.Count).End(xlUp).Row + 2
   ws1CopyRange.Copy
      'copy all
   ws2.Range(firstColToCopy & ws2NextRow).PasteSpecial Paste:=xlAll
   Application.CutCopyMode = False
   'all done
   Set ws1CopyRange = Nothing
   Set ws1 = Nothing
   Set ws2 = Nothing

End Sub