duplicate last 4 characters of a cell

I would like to reproduce the contents of a cell but only the last 4 characters.
Raw Data is in column A, and contains text and numbers but I'd like to sort the data using the last 4 characters in the cell.
Each cell in Column A has varying amounts of text and numbers, so any formula needs to look right in cell contents, and only result the last 4 characters of that cell.


So, I'd like to look at Cell A3, then reproduce the last 4 characters in Cell A7.

Is this possible?