NEW YORK — Noah Wyle is set to star as a Third Reich mastermind in the Euro co-production “The Populist,” to be directed by Ted Kotcheff from a script by Oscar-winning “Gandhi” scribe John Briley.The actor will work on the $20 million film in Germany and Austria in May, on his next “ER” hiatus. Briley’s script is based on “Hitler: The Missing Years,” a memoir by Ernst Hanfstaegl, who helped Adolf Hitler wrest power in post-WW I Germany and ushered him into the upper social circles he needed to finance the Nazi party. The film will be produced by Christian Von Bentheim and William J. Immerman, through Intellectual Property Finances, a British Virgin Islands production and financing company. Foreign sales will be headed by Moonstone Entertainment, and domestic distribution rights are up for grabs. Hanfstaegl was a German-American who was a buddy of Franklin D. Roosevelt at Harvard. He and his bride moved to Germany after WWI. After helping Hitler rise to power, Hanfstaegl convinced himself he was the sole voice of moderation between Hitler and hard-line advisers, but he was eventually forced to flee Europe in 1938. Eventually, he served as FDR’s chief adviser on Hitler during WWII. Inside story The pic will show how a charismatic zealot could persuade an entire nation to follow his twisted agenda. Directors such as Paul Verhoeven have toyed with the idea of a film on the young Hitler, though many fear that a film giving any sympathetic characterization of Hitler as a potential critical and B.O. disaster. Makers of “Populist” believe the key is to focus on the seduction of Hanfstaegl and the lifelong guilt he bore for his role in the Third Reich. “Hanfstaegl was part of the inner ring, and felt tremendous guilt for being seduced by a monster and becoming chief promoter of the viper,” said Kotcheff. “Hitler was a shabby corporal when they met, and Ernst took him into circles he never would have been able to crack, which got him the money he needed. “Ernst honestly felt after hearing him speak that Hitler was the answer to the manifold problems Germany faced, and that only Hitler’s charisma could keep it together. He never showed his true colors until much later.” With most roles for actors his age limited to angst-ridden youngsters, history buff Wyle committed to the script right after reading it. “Not many people know about Hitler’s press rep, this Harvard kid who grew up with people like Mark Twain visiting his home, but who chose to live in poverty in Germany,” said Wyle. “He was thrown a bone by an American army officer to hear Hitler speak and report back on who was there. He was enthralled by what he heard, by this man who was a terrific speaker but totally unpolished.” This will be the second feature starring role for Wyle after “The Myth of Fingerprints.” Kotcheff has directed such films as “The Apprenticeship of Duddy Kravitz,” “North Dallas Forty” and “First Blood.” Wyle’s repped by the IFA Talent Agency.