BERLIN — German pubcasters are taking a radical approach as they seek to shed their stodgy, geriatric image in an effort to attract more youthful auds.

For ZDF, a cutting-edge, interactive experiment appears to have paid off. In April, the pubcaster aired a 50-minute TV movie called “Wer rettet Dina Foxx?” (Who Saves Dina Foxx?), about a young woman framed for the murder of her ex-boyfriend.

Viewers could then register online and participate in a three-week-long investigation to help Dina prove her innocence and identify the real culprits.

Produced by Berlin powerhouse Teamworx, online content shingle UFA Lab and ZDF’s co-production arm Das Kleine Fernsehspiel, a showcase for new talent and experimental works, “Dina Foxx” premiered April 20 in a latenight slot that was pushed back due to a live soccer match that went into overtime. Although it attracted fewer than 700,000 viewers, it achieved an 8.2 share, well above the pubcaster’s after-midnight average.

But for the interactive, cross-media production that remained permanently accessible online, TV ratings were not all that relevant.

More than 1,000 users registered to participate in the online forum, generating more than 14,000 comments as they discussed clues and suspects. Websites dedicated to the movie garnered some 2 million page views while the 55 “Dina Foxx”-related videos on the ZDF site and on YouTube, which provided users with clues and information, were seen some 200,000 times.

Claudia Tronnier, head of ZDF’s Das Kleine Fernsehspiel, says the project “was a huge success in using an Internet crime story to transform the classic lean-back medium into a community of players who came into contact, exchanged information and helped each other.”

The project is one of a number of interactive TV skeins with Internet tie-ins. ZDF is producing a sci-fi series that got its start as a Das Kleine Fernsehspiel Internet series, “Ijon Tichy: Raumpilot” (Ijon Tichy: Space Pilot). Loosely based on the works of Polish writer Stanislaw Lem, the quirky series follows an Eastern European space explorer who travels the gal-axy in his three-bedroom rocket (whose interior happens to resemble a classic Berlin apartment) looking for adventure and exploring strange new worlds.

While the pubcasters eagerly embrace the convergence of TV and Internet in their bid to attract younger auds, commercial rivals are banking on Hollywood and high-profile international series to maintain their lead among the key demo.

USA Network’s “Royal Pains,” about a reluctant young “doctor for hire” to the rich and famous, premiered last week on leading commercial channel RTL Television, where it airs Tuesday at 10:15 p.m. “Royal Pains” proved a hit for RTL, scoring a 21.1 share among the 14-49 demo and an average 3.13 million total viewers. The show replaces “Psych,” another USA Network series that has seen its ratings slide in the past year. RTL pulled the series only six episodes into season four, having attracted an average 2.58 million viewers and an 11.6% share. The recent episodes of “Psych”

still faired better among its key 14-49 demo than all of season three, but RTL programmers are hoping “Royal Pains,” set among Hamptons’ high society, will do better at piquing the interests of viewers.

The broadcaster will follow the show’s first season with another USA Network series showcasing high-class shenanigans, the hit Matt Bomer starrer “White Collar,” about a con man forced to partner with an FBI agent.

RTL has had dibs to “White Collar” since last year but it was unclear until now whether the show would air on the group’s main channel or on affiliate Vox, which airs USA Network’s spy actioner “Burn Notice.”

RTL’s top-rated U.S. shows remain “CSI: Miami,” “House M.D.” and “Bones.”

Vox, which focuses largely on U.S. fare, has seen increasing ratings success with “Law & Order: Special Victims Unit.” The 11th season of the show has enjoyed an average 8.8 share in its Wednesday night slot. Likewise, “Law & Order: Criminal Intent” and “CSI: NY” continue to perform strongly in their Monday night slots.

Rival Sat.1 has also seen muscular ratings from “Hawaii Five-0,” its hit Sunday night series, which has achieved shares of up to 14.5% among key target viewers.

Other broadcasters have been less fortunate with their international series. U.K. sci-fi skein “Primeval,” Syfy series “Eureka” and Fox’s “Human Target,” which make up the Monday night lineup on Sat.1 affil ProSieben, have performed disappointingly.

Likewise, prospects for Syfy’s “Warehouse 13” look dim on RTL 2, where the show has been in descent since premiering impressively in April.

Yet with the L.A. Screenings running through May 28, there’s plenty of U.S. series on offer to tempt Teutonic broadcasters looking to add some edge to their lineups.