Complex Calculations

[Norman Frederick <normfred charter net>]

I am trying to create a spreadsheet to keep track of my wife's stock 
transactions. I want it to track the info we need to furnish the IRS on 
tax returns. Is there a way to create a formula or script that will run 
in a cell to:

Read the dates in two cells.
   Determine the number of days between the two dates.
   Evaluate the number of days as greater or less than one year.    
       Subtract numerical data from two cells.
               Place the result in a specific cell, based on the time 
being more                     or less than one year.

I have found nothing so far that addresses this type operation.
All help and suggestions will be greatly appreciated.
If this is not an appropriate post, please excuse me.
Fred