I don't know for the NSL in 2300, however, IIRC, it works out to something like this...
Z=sin(a)*d
d'=cos(a)*d
X=sin(r)*d'
Y=cos(r)*d'
where
a = ascension/declination (in rads, grads, or degrees...)
r = right ascension in (in rads, grads, or degrees...)
d = total distance to star
d' = flat distance to star as viewed from +Z or -Z