Details = ThisWorkbook.Worksheets("sheet1").Range("N")

with ThisWorkbook.Worksheets("sheet1")
  Details = .range(.cells(2, "N"), .cells(.rows.count, "N").end(xlup)).value
end with

Dim details As Variant, mydata As Workbook

with ThisWorkbook.Worksheets("sheet1")
  Details = .range(.cells(2, "N"), .cells(.rows.count, "N").end(xlup)).value
end with

Set mydata = Workbooks.Open("C:desktopbook2.xlsx")

mydata.Worksheets("template").cells(.rows.count, "B").end(xlup).offset(1, 0).resize(ubound(details, 1), ubound(details, 2)) = YourRef