Chances were few and far between on the bobbly Kassam Stadium pitch and, although City have gone nine games without a win, Mills said: "Don't knock draws. We're getting closer to 40 points.
"My players' desire to win headers and win tackles, and make sure we got something out of the game, was tremendous."
He added: "I thought we were excellent. It was a real battle, with a lot of play in the middle of the park.
"I'm delighted with the clean sheet and delighted with the point and we keep going onwards and upwards.
"The back four showed we were solid, worked hard and got me the clean sheet.
"We know we need a little more in the last third but for us at the moment it's about not losing games. We have worked hard all week and carried that through into the game.
"My players' desire to get something from the game was fantastic."