The creative midfielder is aiming to help the club win a place in the second tier following his switch from Manchester City.
McDermott, who joined until the end of the season and would also be available for any potential play-off matches, made his first appearance for Cherries in last weekend's draw against Charlton Athletic.
The 21-year-old then earned praise from boss Lee Bradbury after producing an eye-catching performance in Tuesday's reserve team friendly win at Reading.
McDermott is in contention to feature in tonight's London Road clash against Peterborough United (7.45pm) and he is hoping to boost Cherries' chances during the run-in.
Asked what his aims were, he told the Echo: Just to try to help the team towards promotion. Any way I can do that, that is what I will be looking to do.
I wanted to come somewhere where every game meant something, coming towards the end of the season.
We have got eight games left and they are all like cup finals, so it should be good.
Training has been good and I'm just hoping to try to be a part of the team and success.
Bradbury was impressed by McDermott's display at Reading. He said: Donal played really well. He is very creative and is quick and sharp on the ball.
He looks to open up teams and I thought he was fantastic for the 45 minutes he played.
He is a good quality player and that is why we brought him here to have strength in depth. He has certainly given us that.
Meanwhile, Cherries goalkeeper Shwan Jalal is aiming to return from a back problem in time to face his former club this evening. He took part in training earlier this week.
Boss Bradbury revealed striker Michael Symes could have a late fitness test on a groin problem, while defender Mathieu Baudry looks set to miss out after sustaining a groin injury in Tuesday's friendly.
n Midfielder Harry Arter is back at Dean Court following a one-month loan at Carlisle United. Carlisle boss Greg Abbott had been keen to extend Arter's stay but Cherries opted to recall the playmaker after the deal finished yesterday.
But three players who have been loaned out are striker Lyle Taylor, goalkeeper Dan Thomas and defender Mitchell Nelson.
Taylor has joined Woking, Nelson has moved to Lewes and Thomas has gone back to Dorchester, where he spent time earlier in the campaign. Cherries confirmed all the deals were due to expire on April 30, although Cherries have a 24-hour recall option on stopper Thomas.
Peterborough: (from) Lewis, Whelpdale, Bennett, Zakuani, Kennedy, McCann, Lee, Rowe, Boyd, Mackail-Smith, Tomlin, Basey, Frecklington, Langmead, Davies, Mendez-Laing, Ball, Taylor, Jones.
Cherries: (from) Stewart, Smith, Cooper, Pearce, Wiggins, Feeney, Robinson, Hollands, Pugh, Dalla Valle, Fletcher, McDermott, Ings, Stockley, Purches, Lovell, Partington, Arter, Williamson, Jalal.