Dealing near the Closed - method

I'm pulling together a spread sheet which combines Directors Deals data and Results Dates. The aim is to identify which directors have bought stock imediately prior to the Closed period. If nothing else this can flag up stock for further research. I'm filtering a fairly long list to show only those deals which:

• Are more than £15,000 in value
• Represent an increase of 5% + of the total
  
• Or a new holding
• By the Chairman, Chief Exec or Finance Director
• With Companies reporting in the next three months
• & Deals in the last three months
  

Later it will be worth looking at which Directors have a record of buying before strong positive results.