as long as the pads on digitakt send note out messages, you should be fine, as you can assign note in values on the ND2.
albeit you won't have velocity on the digitakt pads directly, you will have to sequence in velocity values after recording the notes.
in addition to velocity you will have CCs.
i use the extremely popular rhythm wolf to sequence the nordrum2. it has velocity sensitive pads, sort of. but it can't sequence CCs.
as to recording the external pads for ND2 on the digitakt, i don't know... i don't own digitakt.
P.S. another great option for sequencing AND recording norddrum MIDI data is octatrack.