The assistant manager was handed control of first-team duties following Ian Holloway's departure last week and takes control of his second match at the helm when the Eagles travel to West Brom on Saturday.
The south Londoners have so far struggled on their return to the Barclays Premier League, losing all but one of their nine matches.
There have been suggestions their lowly position has put off some candidates for the vacant managerial post, but Millen insists there is enough time and talent for Palace to beat the drop.
"There is enough points to play for to stay up," the caretaker boss said.
"We have got to be better than three other teams and if you can get a win or a point even on Saturday, it is a start.
"We are not adrift yet. I mean a couple of good results and we'll be within touching distance of other teams.
"We've got to stay positive and looking forward to the game on Saturday.
"I can only speak from myself, working with the group day in and day out.
"There is still belief there. I think we've got enough talent in the squad to compete with, if you like, five or six other teams in this division.
"You only have to be better than three others to survive and I feel where we are at the moment we can do that."
Millen reiterated in his pre-match press conference that he would not be applying for the job on a permanent basis, believing a fresh view is needed to turn things around at Selhurst Park.
Tony Pulis, Chris Coleman and Martin O'Neill are the bookmakers' favourites to take over at Palace, while former Scotland manager Alex McLeish has confirmed his interest.
"There are a lot of good names being bandied around out there," Millen said.
"I think it is hard for the chairman to make a decision quickly. I am sure he will speak to a lot of people and have a second round of interviews.
"It takes time and we've managed to give him that, so I am delighted to be in charge this Saturday."
Asked in particular about former Palace defender Coleman and McLeish, Millen added: "They are managers that have managed in the Premier League and been successful in their own right, like a lot of the names bandied about.
"Chris Coleman is obviously an ex-Palace player, so the fans will know him, and Alex McLeish has an excellent record.
"They are big names and I can understand why big names want the job because it is a well-run club.
"We are in a difficult position but I think potential managers would have seen the lads last weekend and thought 'I've got a group I can work with'."
Prospective managers will have another chance to look at Palace at the Hawthorns, which could prove Millen's final match at the helm.
Palace co-chairman Steve Parish is hoping to appoint a new boss by the start of next week, although the former Bristol City manager may stay on for the clash against Everton.
"We are looking good fitness-wise," Millen said of the West Brom match.
"We had a few knocks earlier in the week from Saturday's game and they have cleared up.
"The squad is fully fit and I have a few selection problems, but I have just been delighted with the players and their response this week.
"It has been positive and we spoke on Monday about trying to build something here even though we lost on Saturday there was a lot of positives from the game.
"That is what we've got to try and do - build it up from the bottom and any bits of success we can gain we have to hold on to and build on."
Source: PA
Source: PA