Need Help with this stem function

From: grider1_at_[hidden]
Date: 2001-09-12 08:07:28

std::string stem (const std::string& word)
//  Tries to guess the stem form of an English word by 
//applying the following rules:  (# and % stand for any 
//consonant, and @ for any vowel [aeiou].
//
//  If word ends in:   replace it by:       example:
//       ies                 y            flies => fly
//       ied                 y            carried => carry
//       ier                 y            merrier => merry
//       iest                y            merriest => merry
//       ##ed                #            hitted => hit
//       ##ing               #            hitting => hit
//       ##er                #            hitter => hit
//       ##est               #            hottest => hot
//       %@#ed               %@#e         glided => glide
//       %@#ing              %@#e         gliding => glide
//       %@#er               %@#e         glider => glide
//       %@#est              %@#e         palest => pale
//       #ed                 %#           barked => bark
//       #ing                %#           barking => bark
//       #er                 %#           colder => cold
//       #est                %#           coldest => cold
//       #s                  #            things => thing
// If none of the above rules apply, then the word is 
//assumed to be already in its stem form.  This function 
//returns the stem that it guesses. [Note that these really 
//are guesses - it isn't hard to find words on which 
// these rules fail. E.g., "pies"]
{
  return word;
} 

I have worked on this some on paper. I understand that it takes a 
word like coldest and should convert to cold but my thoughts is ok I 
know there will be a function to check for the certain 
vowels/constants. I am curious for I don't have much to go on how to 
get started in this direction. I'm reading a book that is using a 
spell checker program from building it up and algorithm books just 
give you the one or two word sentences and you have to figure the 
rest. I was just hoping someone done something similiar to this and 
could just give me a point in the direction. Thanks and have a nice 
day.