Acknowledging that automatic promotion hopes are now all but over, the Scot said: "I am delighted that we are even challenging the likes of Newcastle and West Bromwich Albion.
"If we can cement a play-off place, it will be a terrific achievement."
A top six finish looks all but secured with Forest holding an eleven point gap on Blackpool in seventh place but their grip on third spot has been loosened by Cardiff's recent good form.
A late winner in the South Wales derby against Swansea means the Bluebirds, who travel to the City Ground on Easter Monday, could overtake the Reds with a win in the live televised fixture.