Using the macro recorder, I came up with the following:
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Sub Macro1()
'
Workbooks.Add
End Sub
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Before doing this, though, define sourceWorkbook = activeworkbook.name,
and repeat for new workbook, so you can easily switch between them.
Resulting in:

Dim sourceWorkbook, destinationWorkbook As String

sourceWorkbook = ActiveWorkbook.Name
Workbooks.Add
destinationWorkbook = ActiveWorkbook.Name