Discnumber, Track Number

I would prefer to number my tracks as follows:
Use Discnumber (1,2...)
and
Track Number (01,02,)........................combined as

101 Title1
102 Title2
103 Title3
201 TitleX
202 TitleY

212 TitleZZZ

Being hopeless at this kind of stuff I have no idea how to do this as an "automatic process"
Help!

Thanks

Create an action of the type "Format value" for TRACK
Enter as format string: %discnumber%$num(%track%,2)
Run once per track.