Copy Rows - Ignore duplicates

Hi there,

I've created a macro which will send all rows from a worksheet to another worksheet in a different workbook. Currently it will send everything from column A - Column U until there's an empty row.

I was wondering if there is a way to skip duplicate rows. So for example if the cells in row A2:U2 matched a row in the second workbook, it would skip sending that row!

Below is the code I'm using, and I've attached an example spreadsheet to give a clearer view of what I'm trying to achieve.

Thanks for any help in advance

Sub uploadmacro()
    Dim SourceRange As Range
    Dim DestRange As Range
    Dim DestWB As Workbook
    Dim DestSh As Worksheet
    Dim Lr As Long

    With Application
        .ScreenUpdating = False
        .EnableEvents = False
    End With


    If bIsBookOpen_RB("mastersheet.xls") Then
        Set DestWB = Workbooks("mastersheet.xls")
    Else
        Set DestWB = Workbooks.Open("T:\Folder\Folder2\mastersheet.xlsm")
    End If
    Set DestSh = DestWB.Worksheets("masterachieved")

Lrs = LastRow(ThisWorkbook.Sheets("examplesheet"))

For T_ros = 2 To Lrs
    Set SourceRange = ThisWorkbook.Sheets("examplesheet").Range("A" & T_ros & ":" & "U" & T_ros)

    Lr = LastRow(DestSh)
    Set DestRange = DestSh.Range("A" & Lr + 1)

    With SourceRange
        Set DestRange = DestRange.Resize(.Rows.Count, .Columns.Count)
    End With
    DestRange.Value = SourceRange.Value
Next T_ros

    DestWB.Close savechanges:=True

    With Application
        .ScreenUpdating = True
        .EnableEvents = True
    End With
End Sub