"We're still floating in seventh heaven, on a Montreal cloud," says Belgian director Nic Balthazar following the success of his directorial debut Ben X at the Montreal festival in September.

The film is based on When Nothing Was All He Said, a novel Balthazar wrote about a young autistic boy who is bullied to death. The novel spawned a successful play, Nothing. One of Belgium's most celebrated production companies MMG, whose credits include Brussels By Night and Crazy Love, decided to back a film version.

Ben X was received rapturously in Montreal. It took the audience award, the Ecumenical Prize and shared the main competition award, the Prize of the Americas. Paris-based Films Distribution has world sales duties.

"It was one of the most thrilling weeks of my life," says Balthazar, a TV presenter in Flanders and former film critic.

That the film's initial press screening was at 9am on a Sunday morning did not fill him with confidence. "I know press screenings can be quite savage. People walk out or sit writing in the dark."

For Balthazar, the film's appeal lies in its universality. "For any parent, it's your worst nightmare that your son or daughter will be bullied at school or that they will be unhappy and even think about suicide," he says.

The subject matter may sound grim but the director points out he has not made Ben X as a social realist tract. He describes it as a "feelgood, feelbad film." Video-gaming plays a central part in the storytelling, providing the beleaguered protagonist, played by Greg Timmermans, with a way of escape. The film boasts some startling technological endeavours. Balthazar struck a deal with Codemasters, the company behind multi-media online role-playing game Archlord.

"This is what really makes the film revolutionary," suggests Balthazar. "It's the first film I know of where we actually directed films in cyberspace. We had six 'gamers' sitting round our desk in Brussels with my screenplay and then had people from Codemasters record it on a hard disk."

In Belgium, where the film did very brisk business on its release in late September, Ben X has provoked a national debate about bullying and been selected as the country's foreign-language Oscar entry.

But Balthazar has not yet given up the day job. He still directs episodes of a popular Flemish travel show for TV, even though feature opportunities are opening up for him. US talent agents are reported to be courting both the director and his producer Peter Bouckaert of MMG.

"This is one of those rare crossover films where you have an author's film that can go out to a big audience," suggests Balthazar. "When you try to make a film that's both popular and innovative, with an edge to it, you can end up flat on your ass between two chairs."

As for the future, he takes solace in a remark once made by Jim Jarmusch: "If you don't know where you're going, it's a lot harder to get lost."