The Activecell belongs to a window or the application--not the worksheet.

So one way is to go to that worksheet and look at the activewindow:

   Dim myRow As Long
   Dim ActCell As Range
   Dim CurSel As Range
   
   Application.ScreenUpdating = False
   
   Set CurSel = Selection
   Set ActCell = ActiveCell
   
   Worksheets("sheet2").Select
   myRow = ActiveWindow.ActiveCell.Row
   MsgBox myRow
   
   Application.Goto CurSel
   ActCell.Select
   
   Application.ScreenUpdating = True