Copy/Paste Multiple Columns in VBA which has Picklist

[ShilpaDell]

Hi,
I am trying to validate e Values I am pasting Excel which has the columns of PickList.
If I know the copy and paste is multiple rows for single column .Below is the code. But if the paste is multiple columns and Rows how will it work?
and The columns 4 and 10 are only have picklist.

Public CurRange As Range
Public CheckReasonCodeRange As Range
Public CheckLegacyIDPrefix As Range
Public str As String
Dim va As Variant
Dim length As Integer
 
Private Sub Worksheet_Change(ByVal Target As Range)
     Set CurRange = Target
     Set CheckReasonCodeRange = Sheets("Codes").Range("A:A")
     Set CheckLegacyIDPrefix = Sheets("Codes").Range("X:X")
    'checks the current column is a drop down(Reason Codes) or not
    If ActiveCell.Column = 4 Then
      
      'Checks the Multiple rows copy paste
        If Target.Cells.Count >= 1 Then
            length = Target.Cells.Count
            For i = 1 To length Step 1
                If length = 1 Then
                    str = Target.Cells.Value2
                    If str = "" Then Exit Sub
                Else
                    str = Target.Cells.Value2(i, 1)
                    If str = "" Then Exit Sub
                End If
                If IsError(Application.Match(str, CheckReasonCodeRange, 0)) Then
                    MsgBox ("The value You Enetered is not in Reason codes List Please Select Value from Drop Down List:" & str)
                    CurRange.ClearContents
                    Exit Sub
                End If
            Next
        End If
    End If
    
     If ActiveCell.Column = 10 Then
      
      'Checks the Multiple rows copy paste
        If Target.Cells.Count >= 1 Then
            length = Target.Cells.Count
            For i = 1 To length Step 1
                If length = 1 Then
                    str = Target.Cells.Value2
                    If str = "" Then Exit Sub
                Else
                    str = Target.Cells.Value2(i, 1)
                    If str = "" Then Exit Sub
                End If
                If IsError(Application.Match(str, CheckLegacyIDPrefix, 0)) Then
                    MsgBox ("The value You Enetered is not in Reason codes List Please Select Value from Drop Down List:" & str)
                    CurRange.ClearContents
                    Exit Sub
                End If
            Next
        End If
    End If
End Sub

Please Help.Thanks in Advance