Here is the formula you wanted.
If your present/desired bearings are within 60 degrees , then :-
Inbound: desired bearing, present bearing plus 30 degrees (in that order).
Outbound: desired bearing, 45 degrees, present bearing (in that order).
If more than 60 degrees, then go direct to the station.
As far as outbound bearings and radials are concerned they are both the SAME. They both radiate out from a point. When tracking outbound fron an ndb to the threshold it is far better to use "desired radial" and say to yourself -"what radial do I want, What radial am I on" and simply turn towards the desired radial. This is a fool-proof method of tracking regardless of the wind, and will prevent you from turning the wrong way (which is the biggest problem with tracking to the runway with a crosswind using that "bearing" method).
Hope that helps you. Merry Christmas.