Mental block - how to set a range with sheets and cells

I'm at a mental block. This is inside a private sub that calls it and provides the EndRow argument. I it works, but only if I first "select" the sheet on which I want the formula placed:

Dim formRange As Range
Set formRange = Range(Cells(2, 11), Cells(EndRow, 11))

With formRange
  .FormulaR1C1 = "=COUNTA(RC[-9]:RC[-1])"
End With

What I'd like to do is add the sheetname to the set statement so I can avoid selecting or activating the sheet. Something like this:

Set formRange = Sheets("Report").Range(Cells(2,11), Cells(EndRow, 11))

I know that's incorrect, but I'm at a mental block on it.