Try the likes of 
Sub Blah()
Set Source = Range("A1:A15")
Set Destn = Range("B1")
For g = 1 To 12
  For h = g + 1 To 13
    For i = h + 1 To 14
      For j = i + 1 To 15
        Destn.Value = Join(Array(Source.Cells(g), Source.Cells(h), Source.Cells(i), Source.Cells(j)), ",")
        Set Destn = Destn.Offset(1)
      Next
    Next
  Next
Next
End Sub