Post Selected Columns into next available column

[jgcramer]

I am trying to write a macro that copies specific columns and then inserts them into the next available column. This is what I currently have

Sub addnewyear()

    Columns("D:O").Select
    Selection.Copy
    Cells(Selection.Row, Columns.Count).End(xlToLeft).Offset(, 1).Select
    Selection.Insert Shift:=xlToRight
End Sub

I'm getting selection not valid, I believe it's because its not selecting the entire column which i want it to do. Any suggestions? Thanks for the help.