The answer is, you don't really want to do this.
Duplication of data within a table tend to make programming solutions more complex instead of simple. Imagine duplicating a value 5 times and then needing to change it with code - 5 times.
Build a query based on the field in your table...and extract/concatenate/calculate the values you need.
Then, anywhere you wish to use this new "field" - reference the query, not the table.
Mike