dun tink just use!
ok actually it depends on how old it is. and you mentioned cupboard. so it wasnt stored properly, unless your dad's cupboard is like below 20 degrees hehe!
i tink maybe, maybe hor, u need to over expose for a very expired roll of film, but really there isnt a definitive guide as far as i know.
*personally if its a cheap roll of film i wouldnt bother cos it doesnt cost much to buy a fresh roll anyway, and if nothing comes out its a waste of money, plus you may have been shooting something that u really want. but if its slides i will just whack, simply cos the slides more expensive and worth the risk to process it. still this is my opinion nia.
as for pushing film, try this short article:
http://www.photonaturalist.com/photoforum/Articles/Pushing.pdf