The controversial midfielder was handed the captain's armband on his debut in Monday night's 0-0 draw against former club Newcastle.
Barton was one of six signings to make his R's bow in the draw at Loftus Road.
The 29-year-old was always expected to make his debut after his high-profile move from Newcastle, but his appointment as captain for the season came as a surprise.
Warnock, whose team were unlucky not to take all three points, insists he has made the right decision in giving Barton the armband previously worn by Adel Taarabt.
He said: "It was just a logical thing really. I had a chat with Adel last week. Adel was straight away right about it. He appreciates how far we have come now and that we need to drive on now.
"We need somebody as our leader. He (Barton) epitomised what we are about tonight (Monday). I thought he handled himself well.
"He just grabbed hold of us. We will have our moments where things won't go so well, but you have to have that in any healthy relationship."
Shaun Wright-Phillips was the most impressive of the six players to make their debut after the spending spree of new owner Tony Fernandes kicked in towards the end of the transfer window.
The former Manchester City winger had a delightful chip cleared off the line and looked lively throughout, although he should have buried a second-half chance when clear in the box.
Barton was industrious in the centre of the park, picking out his new team-mates easily while switching positions several times.
Barton claims to be a reformed character from the man who was jailed for assault three years ago.
The midfielder signed autographs for the travelling fans after the game and Warnock added: "I haven't seen many faults with him in the last couple of years.
"It's better for him here in London on the family side of things and on the field you will see a different type of person as well because he knows it's an exciting time with Tony coming in."
Speaking about the stalemate, Warnock added: "I couldn't have asked for any more really. We only really had four training sessions together with all the new signings.
"You don't always dominate for 90 minutes but we weren't far off tonight (Monday)."
Newcastle never looked like scoring, with Leon Best having their best chance of the game with a weak shot which was easily saved by Paddy Kenny.
However, the club are now fourth in the league with eight points from their opening four matches.
Newcastle boss Alan Pardew was disappointed that his team did not create more chances, but was happy to take a point.
"I am not disappointed we did not get any more from this game because we did not deserve any more," Pardew said.
"We went with two strikers but with all the exuberance here with all the players they have brought in, maybe I should have helped my central midfielder out.
"Offensively we never created enough to win the game, but on the plus side, defensively we showed what we have been doing all season.
"We don't give much away and there is a spirit in the group that makes it hard for teams to beat us.
"Our flair players were just a little bit off-key tonight (Monday). Sometimes when you don't play well, you get beat. We didn't get beaten tonight (Monday)."