on rereading the entire thread i find that objws is a workbook object, where you need to be working with a worksheet object

vb Code:
  1. set omysht = objws.sheets("sheet1")
  2.       r = omysht.range("a65536").End(xlUp).Row +1  ' next empty row
  3.       omysht.Cells(r, 1) = DatePart("yyyy", Now)
  4.       omysht.Cells(r, 2) = DatePart("ww", Now)
  5.       objexcel.ActiveCell.FormulaR1C1 = "=RC[-2]&""_""&""FW""&RC[-1]"
  6.       omysht.Cells(r, 3) = ActiveCell.FormulaR1C1