pool tile replacement (small area)

I have approximately 3 feet(length) of 6 inch tiles to replace do to age around one area of the pool.Unfortunatley, the tile sheets are no available anymor so I will have to improvise. After removing said tiles I was informed by the pool folks that I could use white cement to backfill where I remove the tiles and immediately set the new sheets of tile into the cement and spread a thin layer of the cement over the tile as grout filler. Makes sense I think? Any suggestion as to what product I should use via Home depot or Lowes, they also said I should caulk the area between concrete deck and flagstone coping--suggestions again?

thanks

Mike

PS: Should I do this after I partially drain pool for the winter and let it cure???