VW Lupo 3L Gear Problem

Hallo, unfortunately, I'm having a problem again that I can't solve. Maybe you guys are smarter than me.
A friend of mine disassembled and reassembled a DSG gearbox from a Lupo, and now the engine doesn't respond to acceleration. It only responds in gear O. Do I need to re-activate the gearbox using VAG-COM? I hope you can help me.
this car is a Lupo 3L, 1.2 PDTDI, year of manufacture: 99, with DSG gearbox....

[Translating...]

www.lupo3lclub.de
Die kennen sich besser mit dem Getriebe aus. Ist übrigens nur nen "halbes" DSG im Lupo 3L.

Gruss

Olaf