Pick up Live Neutral & Earth from a celiling rose below - run it to the place where you want the light to be - either fit a ceiling rose or a fully insulated 4 way terminal box (with a lid) run a cable from the terminal box to the Switch position (presumably near the loft hatch).
Wire up as per this diagram...
http://www.flameport.com/electric/lighting_circuits/lighting_ceiling_rose.cs4
Or call in an electrician and have it done properly and safely - they need the work!
Good luck...Take care...
Peccavi, December 2009
