I would like to find all the unique words in a text file and store them
in an Excel 2010 spreadsheet. I am looking for a reasonably
efficient method or algorithm to achieve this.

I was thinking, how about save all the words that begin with "A"
in the A column, all the "B" words get placed in the B column,
etc...

Also, each word should only be stored ONCE in the spreadsheet,
regardless of lowercase, uppercase, mixed, etc. So, if my text
file contains "apple", "APPLE", or "aPPle", only one instance of
"apple" should appear under the A column.

I'd appreciate anything to help me get started. Thank you.

Robert