Lang, who competes for the NSK Trzic Trifix, jumped his first World Cup competition on January 1, 1997 as part of the 1996/97 Four Hills Tournament in Garmisch-Partenkirchen . As in the following competitions of the 1996/97 season, he clearly missed the points. At the Junior World Cup 1997 in Canada Canmore he won the gold medal with the Slovenian team. A year later he was able to jump into the points for the first time at the World Cup in Kuopio with 29th place. However, it should have been the only time he succeeded in doing this for four years. At the ski flying world championship 2000 in Vikersund he came in 39th place. After he was unsuccessful in the World Cup, he started from December 2001 mainly in the Continental Cup (COC). On January 26, 2002 he managed to win points in the World Cup in Sapporo again. In spite of the only one point he was in the end with 88th place, the highest place in the overall World Cup ranking in his career. In the Ski Jumping Continental Cup he was able to achieve several top 20 placements in the last two years of his career, including two seventh places in Velenje (2002) and Westby (2003). After jumping in Ruhpolding on March 2, 2003, he ended his active ski jumping career.