As he nears his 85th birthday, screenwriter Frank Pierson is gearing up for a new scripting assignment.Pierson has been tapped by Madmedia Entertainment to pen 3D Korean War epic “17 Days of Winter” for helmer Eric Brevig. “17 Days of Winter” is about the pivotal 1950 battle of Chosin Reservoir, in which 12,000 American troops fought a 120,000-man Chinese force in sub-zero temperatures. Pierson’s last produced writing credit is some 20 years ago. “I’ve been like everybody else in the movie business. I’ve been doing scripts that just didn’t get made,” he told Daily Variety . His most recent project fell apart in pre-production when the financing collapsed at the last minute. One attraction of “17 Days of Winter,” he said, was “The money’s there.” But he said he was attracted to the project because, for the first time in his long career, he will get to draw on his own experience as a combat infantryman in WWII. “The most interesting thing about the battle of Chosin Reservoir, from a writing standpoint, was the only people they had to put into the Marine division that went over were leaders from WWII, who were then in their 30s, who were virtually coming out of retirement. Serving with them were 17- and 18-year-old volunteers who had never even been to boot camp. “That gives an opportunity for getting inside those characters. What was it like for these kids who were being mentored by these battle-hardened veterans?” Pierson himself went into the Army on his 18th birthday and served in the Pacific, seeing combat against the Japanese in New Guinea and the Philippines. “I went into combat like these kids in Korea,” he said. “It was a life-changing experience for me.” “17 Days of Winter” is getting unprecedented support from the South Korean government. It is to shoot in South Korea and New Zealand in time for 2012 release ( Daily Variety , Feb. 26). 3D veteran Charlotte Huggins (“Journey to the Center of the Earth”) reteams with Brevig as producer. Madmedia’s Jayson Wan is executive producer. Pierson won the original screenwriting Oscar for “Dog Day Afternoon” and was nommed for “Cat Ballou” and “Cool Hand Luke.” Over the past decade, he’s been busy directing TV and serving as a consulting season on the past season of “Mad Men.” He has also served as prexy of the Writers Guild and the Motion Picture Academy. “By this time I thought I’d be playing golf, but I never had time to learn,” he said.