Here's another way, which, too, depends on functions from the web site;
I didn't take the trouble to declare variables, but of course you should:

Sub abtest1()
Dim arr1()
ReDim arr1(1 To 3, 1 To 1)
With ThisWorkbook.Worksheets(1)
arr1 = .Range(.Cells(2, 1), .Cells(4, 2)).Value
arr2 = .Range(.Cells(2, 6), .Cells(4, 6)).Value
End With
'Add a second column of empty values to arr1
ReDim Preserve arr1(1 To 3, 1 To 2)
'Replace the second column of arr1 with the values from arr2
ReplaceSubArray arr1, arr2, 1, 2
End Sub

If the code is in a general module I would replace the 3rd thru 6th
lines with the following, which better suits my taste:

Set rng = ThisWorkbook.Worksheets(1).Range("A1")
arr1 = Range(rng(2, 1), rng(4, 2))
arr2 = Range(rng(2, 6), rng(4, 6))

I'm not a fan of the Cells Property, and in addition, the above avoids
the need for qualification if Worksheets(1) is not the active sheet.

Alan Beban