Copy the last 3 columns

[msknvg]

Hello guys,

Probably this is a dumb question but i am starting a new job and its my first time with VBA.

Basically, there is an excel file that is constantly updated. I need to copy the last 3 columns of that file to another excel. As simple as that, but my code isn't working... I'm testing with just one column, and it still doesn't work.
I leave the code below.
I can't understand how to define the some stuff that i mention in

Sub Copy()
Dim lCol As Range

    lCol = Cells(1, Columns.Count).End(xlToLeft).EntireColumn
    (how to define the second column?)
    (how to define the third column?)
    Range("how to define the range of 3 columns?").Select
    Selection.Copy
    Application.WindowState = xlNormal
    Windows("Teste 2.xlsx").Activate
    Range("D1").Select
    ActiveSheet.Paste
    Windows("Teste 1.xlsx").Activate
End Sub

I don't know how to define the things I mention in italics.
I don't know if it was too confusing but I would be grateful with any help.

[Bob Phillips]

Why are you trying to copy entire columns to a limited number of rows? I would have thought you wanted to copy entire columns to entire columns, or you would copy a number of cells in columns to another place.

[msknvg]

Oh yes, the objective is to copy entire columns to entire columns!
Already changed the destination range.

[p45cal]

Are the columns next to each other?
Cells(1, Columns.Count).End(xlToLeft).offset(,-2).resize(,3).entirecolumn.Select
or to put it into the clipboard in a single line:
Cells(1, Columns.Count).End(xlToLeft).offset(,-2).resize(,3).entirecolumn.Copy