(Untested): You could also use AutoFilter to show only rows that have
"Delete" (or whatever your formula inserted) in them.
Then use:

Set rngMarkedCells = rngData.SpecialCells(xlCellTypeVisible)

You might stilll have to Copy and PasteSpecial to eliminate the formulas
before doing the AutoFilter method, to prevent the cell values from
changing.
--
Regards,
Bill Renaud