I've just done a DPF regen with my Maxidas DS 708 on 2007 Audi A4 2.0 TDI,  Engine Code BRD. It must be on the Maxisys being a newer scantool,

I was told by Autel Technical the DS 708 would not do a forced regen, mine seams to work OK.

I was guided by the info built into the scantool  on what channels to use.

I borrowed a mates snap-on Verdict the first time on a 2.0 Audi A3,  the snap-on carries out the regen automatically, the same info is available on the DS 708 but has to be selected manually before starting out on the Road .

http://wiki.ross-tech.com/wiki/index.php/Diesel_Particle_Filter_Emergency_Regeneration

Here is the all procedure to do DPF regeneration in VAG group cars.