MZ....
think this will work....bit rusty!
1 Take reciprocal of bearing of NDB.
2 Apply variation, taken from chart
3 Plot bearing from NDB posn on chart.
4 Measure off distance in NM using latitude scale.
(Presume you are using a Lambert Conformal Chart. If using a Mercator with a distance of more than 400
miles you will need to take conversion angle into account )